New Life Games Tech Forums

If you have questions relating to the threads in this forum section, please post them here and not in the individual game repair threads.

Thanks!

RJ

Final Fight :

Ok i got 3 boards for this one. There is one who should work but it says on self test WORK RAM NO GOOD.

Can you help me by telling me where this Work Ram is located on board ? thank you !

            For such an error ,there might chances that the Boot-ROM is faulty as per my experience. Since you have got 3 pcs,then it is better that you first swap them in order to pin point that which of the portion i.e Upper or lower portion is having problem.

That error points to the A board - the bottom board in the 3 board stack. It's one of the 256k SRAM ICs.

The problem is that there is no documentation for which of the many 256K SRAM ICs is bad. You'll have to swap them out one by one until you find the bad one.

RJ

Hi guys, after testing, it appears the A-board (game board) are all fine (all 3), i tested them with my Mercs B-board PCB and they all works.
The pb is on the B-board (motherboard), one of the 256k SRAM is dead or maybe more as channelmaniac said.
I have picked their references, HM65256BLSP-10 and M5M5178P-45.
I suppose from what you said Channelmaniac that the problem is with HM65256BLSP-10 right ?

Also, very sad news, i got today 2 PCB in good condition (no trace cutted as far as i saw), but they are DEAD :(

one is Bad dudes vs dragon ninja, a flat black covered chip with 10 pin marked 'RCDM - I1   86' has been smoking under my eyes !!!!
and the second is robocop, nothing appears on screen, it's like the vsync is ON, with nothing more.....

any idea on what is RCDM - I1 86 will help me, i can't find on google what kind of chip it is, resistor, capacitor, i don't know.

A pic would be very helpful

no pb ! i do that :D

Hi !
just discovered this place and i thaught it might be a good place to ask for some help about my 2 faulty MVS NEO-MVH SLOT1FZS

here is some pictures

(http://img1.uplood.fr/mamu/thumbnails/uy5d_img_8852.jpg) (http://www.uplood.fr/visu.php?url=http://img1.uplood.fr/mamu/uy5d_img_8852.jpg)(http://img1.uplood.fr/mamu/thumbnails/riwl_img_8850.jpg) (http://www.uplood.fr/visu.php?url=http://img1.uplood.fr/mamu/riwl_img_8850.jpg)

(http://img1.uplood.fr/mamu/thumbnails/1y5m_img_8853.jpg) (http://www.uplood.fr/visu.php?url=http://img1.uplood.fr/mamu/1y5m_img_8853.jpg)(http://img1.uplood.fr/mamu/thumbnails/1pft_img_8851.jpg) (http://www.uplood.fr/visu.php?url=http://img1.uplood.fr/mamu/1pft_img_8851.jpg)

One of the slots had a damaged bios (burned ?)
(http://img1.uplood.fr/mamu/thumbnails/eof1_img_8863.jpg) (http://www.uplood.fr/visu.php?url=http://img1.uplood.fr/mamu/eof1_img_8863.jpg)

I replace both bios on both slots with a unibios 2.3 and I now have a picture, but it seems it's lacking some graphics in the first slot and the second one misses graphics too AND have vertical black lines all over the screen.

first one
(http://img1.uplood.fr/mamu/thumbnails/90s9_img_8874.jpg) (http://www.uplood.fr/visu.php?url=http://img1.uplood.fr/mamu/90s9_img_8874.jpg)


Second one
(http://img1.uplood.fr/mamu/thumbnails/hddl_img_8879.jpg) (http://www.uplood.fr/visu.php?url=http://img1.uplood.fr/mamu/hddl_img_8879.jpg)

Both slots have been washed and inspected, I did not find any evident bad traces (looked quickly)

Any ideas ? Thanks !

One of our site moderators Channelmaniac has a repair topic on these types of games

Here is the link

http://newlifegames.net/nlg/index.php?topic=152.0 (http://newlifegames.net/nlg/index.php?topic=152.0)

Wes

Yep, I saw
Just wanted to know his thaughts about it, I'm not really an expert, maybe he could help me out on this.
thanks

Hi
The second slot doesn't have any black lines anymore after cleaning again.
One of the slots had corrosion due to battery leaking. I removed the battery and cleaned the corrosion a much as I could but no still no background graphics.
With the original bios installed I had garbage screen with the click of death.
I don't know where to look at and I don't know how to test the chips (I only have a digital multimeter)
Any help would be much appreciated, thanks !

Hmmm...

That chip is burned. You'll need a replacement for it.

As for the missing graphics, you'll want to check the corrosion affected area for damaged traces. Also look closely at the board for scraped traces on the bottom side that need patching. It's a common problem on those smaller boards.

RJ

thanks for your answer
I replaced original burned bios with a unibios 2.3
I saw on your logs that missing background appeared also when the 74ls244 chips are dead. I only have 74ls245 chips on my board, is it worth it to replace them ?

I looked very closely for damaged traces or hits on the board but did not find any, could they be UNDER some chips near the battery ?
thanks

It's possible but I don't remember what traces are around that battery on that particular board.

Double check for any scrapes or scratches on the board. It doesn't take much to cut through a trace.

74LS244 are buffers and are typically used for buffering address lines. The 245 chips are latches and are used to latch data onto the data bus. I doubt one of those would cause that problem but you never know. ;)

Ok, i'll check one more time.

If I don't find any evidence of damaged traces, where should I look for next ?

Bent pins on the cartridge slot... and make sure the vertical board is plugged into the bottom board. It's possible that they could be partially unplugged.

Hi
I saw on one of the boards that a component is missing

(http://img1.uplood.fr/mamu/thumbnails/db48_img_8884.jpg) (http://www.uplood.fr/visu.php?url=http://img1.uplood.fr/mamu/db48_img_8884.jpg)

Could you tell me what this component is ? it's labelled "PC" on the board

What should I use instead of this missing component ?
thanks

It's a simple bypass cap used for filtering +5v... it's a .01uf monolithic capacitor.

If it's missing you probably will have zero problems. It's not a part that does anything drastic. It just filters the 5v line a bit.

Thank you !

I looked very closely with a magnifying flass and a multimeter for bad traces but did not find any

Vertical board and cartridge slot seems good too.

Any more ideas before I give up trying to repair those things ? :35-

Hello,
Hope this is the right place to post this, if not I apologise.
I have an original X-Multiply PCB running on the Irem M81 hardware. Ive been having a few graphical issues with it and with a quick inspection noticed that 3 of the legs on a rom were heavily corroded just about gone!
I am able to burn a new eprom but this is where I get stuck.
The M81 B board where the roms are located has a jumper switch located at the end of each rom bank with the options of MASK or EP. Currently this is set to MASK and im guessing that EP means eprom?
So, can I just simply swap one of the maskroms out for an eprom or do I have to replaced them all with eproms and change the jumper over to EP?

Hope you can help because I cant find anything about these boards out.
Let me know if you need any more information

Thanks very much

The easiest thing to do would be to check the traces going to the jumper with a multimeter to see what the difference is between the 2 settings. You might have to modify the traces going to the single socket.

RJ

ok, this is what Ive got
when set to MASK (pin 1 & 2), pin 1 goes to number 2 on the chip socket, this is empty when a maskrom is fitted
pin 2 goes to number 22 on the chip socket

when set to EP (pin 2 & 3), pin 2 goes to number 24 on the chip socket (#22 if the 28 pin maskrom is fitted)
pin 3 goes to ground.

Im not too well clued up when it comes to pinout meanings so am a little lost with it.

also forgot to mention earlier, the maskroms fitted are 23c1000 and are 28 pin.

thanks again for your help, your information on this site has already proved very valuable to me on a couple of occassions.

OK,

These should be 28 and 32 pin devices.

Mask = 28 pin equivalent to HN62321 which is VERY similar to a 27C301 EPROM.

EP = 27C010 type EPROM which is a standard JEDEC pinout.

The 27C301 is almost the exact same pinout as a 27C010 - pins 2 and 22 are swapped.

Check to see if your EPROM programmer will program a 27C301. If it will, check pin 2 on the board (Pin 2 as related to the whole 32pin socket) to see if it is grounded. If it is then the 27C301 will be a direct replacement and you can leave the jumper in the Mask position.

If not, use a 27C010 and swap pin 2s and 22 by building an adapter. To do this, take 2 chip sockets. Bend out pins 2 and 22 on the top socket then use some tape and some wires to jumper the pins 2 and 22 around.

Go to http://www.datasheetarchive.com and pull down the data sheets for HN27C101 and HN62321. In there you will see what I'm talking about.

HN62321 is the 28 pin MASK ROM and is equivalent to what you have in there now as a mask ROM.
27C101 is the JEDEC pinout 1Mb EPROM
27C301 is the non-JEDEC pinout 1Mb EPROM which is (mostly... look at pin 2!) mostly pin compatible with the mask ROM.

RJ

I have been learning a lot about eproms and also getting to know my eprom burner a bit better. I have come across a few instances, mainly in forums and once for myself, where certain address pins on the eproms allows access to different areas of the eprom.
For example, on my Irem board I asked you about in my previous posts, I have to read the 23c1000 as a 27c512 eprom, covering pin 22 so it doesnt make contact, and running a wire from GND to pin 22, dump the data, then run the wire from VCC to pin 22 to get the second half of the data. My question is, how do I find out what address pins activate these different areas? Ive checked some datasheets but not 100% on what im looking for really. This is more for curiosities sake than functional at this time but when I get interested in something my tendancy is to run with it obsessively.

Thanks for any help you can give
Jon

Every address line doubles the space on the EPROM for storing data. The highest address line doubles it from 512k to 1024k. What you are doing when grounding it is to access the lower 512k space then the upper when you are tying that line to Vcc (+5v)

You should've used a couple of sockets and some wire to rewire it to fit into a 27C010 or 27C301 pinout and read it as a whole 1Mb EPROM.

RJ

Thanks for the info.
I did eventually end up reading one as a 27c301 after your original advice. I read then as a 512 before i knew what i was dealing with, but now its all becoming clear.

Thanks again, youve been a real big help to me
Jon

Hello Raymond,

I'm back with a problem with a pipi & bibi Toaplan game board.

1) The custom gfx chip had some legs desoldered, with my very thin ironsolder tip i solder them back, the graphic corruption is out.

2) The sound was missing, due a deep cut on a part of the audio circuit part.

I can almost get the sound correctly now, but get Crrrrsshhhhh and the sound is not clear, but i have the music and fx.

My question is : By replacing the capacitors, will the problem be resolved, and is it due to bad capas ?

thanks !

Could be related to missing sound samples on the sound section. The best bet is to check the outputs of the sound section with an oscilloscope before it goes into the amplifier section. If you don't have an oscilloscope then recap it and see if that fixes it since that will be the easiest thing you can do without the scope.

Thank you for this quick'n'fast reply ;) it makes like a parasite noise in the sound. I have an electronic multimeter, could it be enough ?

There is also something else that annoy me seriously, my board has radial caps, but i saw another board of the exact same type, but this one use axial ones.

Could it be also a source of troubles ?

Possible, but unlikely those caps would cause that kind of problem.

You can't really test that audio stuff with a multimeter. Maybe you could build an audio probe? Check Google for schematics.

Have you seen this before - Neo Geo 4 slot, (SLOT4F) - sorted out the main problems, and it works fine with most carts, however, on the odd one, such as metal slug 2, if gives me an error telling me I'm using a bootleg board. (screen image attached)

Any ideas on what could cause this and where I should be looking. (which part of the circuit)

Thanks

Common issue.

Open the cart and take the boards out. Scrub the edge connectors top & bottom with a pink pencil eraser.

If that doesn't take care of it then clean the slots on the board. Instructions are out on http://www.hardmvs.com

Raymond

Actually turned out a bit easier than that!

I looked at the Mame source for inspiration, and it mentions that some carts use the watchdog as part of a security check, that wasn't happening on this PCB - sorted it out and MS2 now plays along with everything else.

Hi!,
    What if the SMD GALS go bad on Tekken 3/Tag?  I mean how to reprogram them as there is no data available...if you have please share

I don't have those GALs dumped.

GAL/PAL/PALCE and PEEL chips are the achilles heel for arcade games. Most are not dumped so if a board has a bad chip you are stuck with trying to find a parts board to pull one from.

They are difficult to dump too. You may have to desolder them to be able to put them in a reader... and some have security fuses blown so you can't read how they were programmed. If this is the case the only thing you can do is try different combinations of inputs on the chip to try to reverse engineer the programming based on the outputs you get. I've never tried this so I can't offer any steps on how to do this.

If you have access to an ABI Boardmaster, then I did a script that will dump all of the IO conditions for the PAL / GAL, and a guy called Charles Macdonald did some code that will convert that back to compatible code to re-create the PAL. He also did some hardware to dump PAL's.

It works on combination PAL's, (hopefully) gives enough info to allow you to manually reverse engineer registered ones.

My page is http://www.arcades.plus.com/paldump.htm (http://www.arcades.plus.com/paldump.htm)

Thanks!

Those boxes look $$$$. I didn't see any on Craigslist or eBay but will look around to see how much I can pick one up for.

RJ

Hi,
Ive got a Neo Geo MV1A board thats giving me a Color Ram Bank0 fault.
Write 5555    Read 55FF

Have you any ideas where to start looking? Ive tested RAM 7 and RAM 8 and they test ok. Is bank 0 somewhere else?

Thanks in advance

If it's not in the 64k SRAM chips (CXK-5864) or the chips that interface them then it'll be a chipset issue.

ive check those two so ill put it down to option number 3 of a chipset issue. Beyond my capabilities but thanks very much for your reply once again.

Hi ChannelManiac, first off I want to say thanks for all of the great information you provide here, I wish I had just a subset of your troubleshooting skill.  I see on your incredible technologies page that you've repaired a few older Golden Tees in the past with some pretty bad damage.  I have a Golden Tee Fore! Complete green board that doesn't want to boot.  When trying to enter the test mode (holding start on boot up) I get 6 flashes on the status 1 light which apparently indicates an issue with the ram and possible open trace.  Have you ever come across anything like this before and is it something you might be able to fix?  I've been checking the continuity of the traces on the ram and currently everything is checking out.  I've also looked for any scratches on the pcb but I don't see any that are causing an open trace.  The game was working and just recently stopped and was housed in the dedicated cabinet the whole time so it shouldn't have any crazy physical damage.  The power supply is still providing the necessary 5V at the boot rom and the hard drive is also operational.  I feel as though I've reached my knowledge limit based on the tools that I have available.  Is there something obvious that I could try?  I'm also curious if you knew how long those other Golden Tee boards took for you to fix for cost purposes.  Thanks in advance for any help that you can provide!!

Hi!

Thanks for the kind words!

Those pesky IT boards are difficult to work on. The last 2 I did took a couple hours each and I charged far less than I should've for the time I had invested, but the boards weren't worth a whole lot more than what the charges were.

I haven't worked on that particular type of board you have so I'll tackle this from a generic standpoint. For boards that come up with RAM errors the things to look for are the obvious physical damage from scratches, popped solder from physical hits to the board, or corroded pins/traces from foreign substances such as soda pop, beer/wine, rodent urine/feces, and other gunk that gets on boards. Next check for missing signals on the RAM chips and look for the reasons they are missing. Once that is exhausted then RAM chips have to be replaced one by one.

Sometimes you can get lucky and find the bad RAM with a logic probe or an oscilloscope. As an example, the Neo Geo systems still hold the CPU bus at 0 or 1 levels when the CPU or Backup RAM tests fail. This helps with finding some issues when there is no display telling what RAM is bad.

Raymond

Raymond,

Thanks so much for the reply, unfortunately that's precisely the news that I was dreading.  I'm going to give it another once over to see if I can find anything amiss, but it's looking more and more like I may have to send it out to get fixed.  Is this something you would be willing/have the capacity to take on?  Just reading all of your forum information and seeing some of your past board fixes (all of which I find very interesting, just way over my head), you seem like you do great work.  I was hoping to find someone in the Cleveland, Ohio area but haven't been able to find anyone that does repairs.  My other option would be to send it directly to the maker, IT, to see what they can do.  Have you heard anything about the quality of their repair services?  They would obviously know the most since it's their board, but their rate is pretty pricy, and I'm trying to minimize the damage since I've already got a lot invested in the game.  Thanks again for your time and help.

Kurt

Right now our repair services are shut down as we're moving and I have to get a new workshop built.

Oh, Okay, then I will wish you good luck with your move.  Hope all goes well!!

Hello!!  I'm new to the forum and have been a old school game collector for a few years now.  I'm having trouble finding repair or trouble shooting solutions for the Commodore VIC-20.  I came across one at the swap meet and didn't pay to much for it.  Seller didn't know if it worked.  Came with all the connection cables, tape deck, games and manuals.  All for $15!.  However when I plugged it all up it didn't work.  The red light comes on but the screen is all black.  I've check the RF adaptor and it works.  I check the power adaptor (first gen. 2 prong type) and it works. I opened her up and all looks visually 'ok'  the big capacitor is in good shape and nothing look damaged.  I tried leaving it one for about 1/2 hour to see if she 'warmed' up some of the old connection points and nothing.  Removed and reinstalled all the removable IC chips and nada.  I also tried to see if the tape deck would power up and fast forward and/or rewind and zilch.  Any one know where I could get some troubleshooting info or know what could be the problem.  I knew purchasing it that it might not work but I enjoy trying to bring 'new life' back to old machines.

Thanks in advance!!!

Unfortunately on the VIC-20 it could be a number of issues... bad RAM, back CPU, bad ROMs, etc. Something is causing the computer to just not boot and there will be no video on the display until the computer gets into its startup routine.

Greetings!  New to the forum, and hoping somebody has some insight.

Been digging around online, and not having any luck determining whether I can use an adapter to allow replacing 82S123/82S126 PROM's in a Ms. Pac.

I find some folks who've figured out how to sub a GAL for these, and at least one site is selling 82S123 to 2716 adapters (for older Bally pinball sound boards) - so I'm assuming this *should* work.

My project - I've got a Ms. Pac cabinet, and am configuring it so I can stuff various boards into it - MultiPac, Jr. Pac, etc.  I'm currently working on an extra Ms. Pac board, and attempting to convert it to a Crush Roller (aka Make Trax) board.

Game plays fine; colors are off.  Built two adapters today, for the color PROM's at 4A & 7F.  Adapter at 7F seems to function; regardless of whether I have my adapter in, or the original PROM, the screen looks the same.

However, for the 82S126 at 4A, I'm seeing *different* colors, but not the *correct* colors. 

Any reason why this wouldn't work for my purposes?  Also, the 82S126 has two CE's - do I need to have them both tied to the 2716's CE, or a specific one, or will either suffice?  I've tried tying the first CE, and both, but not seeing a difference.

The PROM code in this case goes from 00 to FF, and I've tried mirroring it all through the 2716 to be safe (00 to FF, 100 to 1FF, ...700 to 7FF).

I've tried burning the PacMan code for this PROM to a 2716 and dropping it in, and the graphics are NOT the same as they are as when I have the actual PacMan PROM installed.  I'm going to double-check all my wiring, but everything checked out immediately after I assembled the PROM.  Could this be related to the 2716 being too slow for this particular use?

My goal is to be able to burn 2716's for various games that are compatible with this boardset, and then swap them in when I swap out the other ROM's.  Those older PROMS are harder to find, can't be erased, and my various burners won't tackle them as well.

Thanks in advance for any ideas/suggestions!

Brent

The 2716 is WAAAAAAAY slower than a PROM.  We're talking 50-70ns vs 300-600ns in speed.

However, the circuit you are using it on is pretty slow. To be sure you'd want to check it with a calibrated oscilloscope or logic analyzer.

Now... The 82S23/123 chips have a single /CE line (the / means active when at logic low) and the 82S126/129 chips have TWO /CE lines. The chip goes active when both are low.

On the 2716 you have 2 enable lines, a /CE and a /OE (chip enable and output enable) and both must be low for the chip to go active. Some data sheets call the /CE line (pin 18) "PD" and the /OE line (pin 20) "/CS" so read the data sheets carefully. In reading the Hitachi 2716 data sheet it appears that if you tie /CE low and use /OE to toggle the chip for activity that the cycle time is far less.

Now each of those chips have varying numbers of address and data lines...
2716: 11 Address lines and 8 Data lines
82S23/123: 5 Address lines and 8 Data lines
82S126/129: 8 Address lines and 4 Data lines

Extra upper Address lines must be grounded. You could use the upper address lines and connect them to switches to switch between banks for different games.

For example: 82S23 uses 5 address lines - A0 through A4. On the 2716 you could use A6 and A5 to toggle through different "banks" or versions of code.
00 - first bank
01 - second bank
10 - third bank
11 - 4th bank

Where the first digit is A6, the 2nd is A5, and 0=ground, and 1 = 5v.

If you leave the address lines floating you are asking for trouble. Same thing if you leave the chip select or chip enable lines floating. Some chips will internally have them tied high or low, but you can't trust all manufacturers to do that or to do it the same way (high or low)

Now... Looking at the schematics for Pac Man - 4A has both /CS lines grounded. The chip is always active. The chip at 7F is used the same way. It's select line is grounded too.

Enjoy!

I have just purchased a Neo Geo Arcade and Bust A Move.  I was curious on how one may reset the high scores.

Flip dip switch 1, power it up, and go into the hardware tests. There you will find a spot where you can press multiple buttons to reset the backup RAM.

Don't forget to turn off dip switch 1 when you power cycle the cab to play the game again!

Appreciate the assistance; the 82S123 adapter seems to work properly, but no luck with the 82S126; tested with various 2716 and 2732 EPROM's; 200ns for the latter - no luck.  Going to go over the adapter yet again to verify that I didn't screw something up in the process, but it just doesn't seem to like it for that particular usage, and may well be speed-related.  I'm likely going to bite the bullet and just spend the ~$150 for PROM adapter used by my burner, and pick up a few blanks.

Thanks again!

Brent

The 82S126 is Open Collector output while the 2716 will be a Tri-State output. You can't always sub one type for the other in a circuit. Sometimes you have to modify things.

Wanted to follow-up in case others look to do something similar...

Short answer - when wiring data and address lines, make sure you match them up - especially when the datasheets don't use the same structure...  In this case, I had D0 through D1 on one datasheet, and D1-D4 on another.  Basically, all four data lines were off by one.  The address lines *did* match, so just a matter of paying attention  :279-

Re-wired those four lines, and it seems to be working pretty well.  Some slight graphics glitches here and there, but definitely very close to where it should be.

Regards,

Brent

Congrats!

Yeah, those pesky data sheets. Some manufacturers start with D0 and others with D1 and it could bite ya! :)

RJ

you mentioned that "These games ARE repairable as long as the CPU is OK". Do you know how to do this, or even a guess at where to start? Thank you for all the awesome info!!

It all depends on the symptoms. If the CPU is finger blistering hot then it's internally shorted. If it's not generating the proper signals on the address/data busses then either the clock is bad or the CPU is bad. There really isn't any other chip that would do that on those boards as they are very stripped down.

Raymond

hi Mr Channel  :131- im from brazil, hard to find any service repair here  :47-

Can u help me solve this problem with my neo geo aes version 3-6 pls?

i didnt found any traces on board, ived looked for 3 days and nothing ...


heres the video: http://www.youtube.com/watch?v=_w6o2mC4M9M

and without cart, blue screen appear, sounds ok ...


cleaned all board, pins, chips and no corrosion, and after 10 min playing starts constantly reboots

Do you u think it could be the LSPC2 , capacitor or bios?
thx

Looks like a problem with an address line on one of the graphics ROMs. Check the cartridge connection for dirty/corroded/bent pins.

Open the cart and clean the edge connections with a pink pencil eraser and clean the cartridge slot. To clean the slot, take some white posterboard and bend it in half once or twice until it's as thick as the cartridge board then put some alcohol on it. Insert/remove it repeatedly several times. That will wipe all the gunk off the cartridge connectors.

If that's not it then you'll have to use a digital multimeter to check the address pin connections from the cartridge slot connectors over to the various chips they go to.

Raymond

And not a problem with the wrong place... I can move the posts around as needed. ;)

thx for quickly reply Ray, :3-

ya i think needed one multimeter, lets see .... cya  :88-

I just purchased my first machine and I'm having a fun time restoring it.  It is a Double Dragon machine with all the original hardware.  The current problem I am having with it is that the board only runs when I have the power supply running at +6VDC and let the machine run for a few minutes.  Under these conditions the machine starts up perfectly with absolutely no errors.  Any less and it gives me a ROM 3 Error and then has all sorts of sketchy behavior.  The most common problem with the ROM 3 Error is that it will freeze shortly into the Attract mode but the music will keep playing.  I pulled all the ICs and checked for any bent pins and I found one on the sound board, which really doesn't help my problem.  The board looks to be in excellent condition with no broken leads, traces, or leaking caps.  Other than the dust it looks brand new.

What should my next step be?  I plan on turning this machine into a street fighter machine in the future so I'm planning on replacing the power supply with something a little more trust worthy.  Should I go ahead with that upgrade and then spend the time chasing voltages around the board or could this be as simple as replacing a single bad component on the board?

6v will fry chips.

I'd start by checking the voltage levels at the ROMs on the game board. If you are checking a 28 pin EPROM then pin 14 is ground and pin 28 is Vcc (+5v)... If it's over 5.25 then lower it. If it's close to 5v yet the power supply is cranked to 6v then you have some serious losses - either thin power cables or bad connections somewhere such as the edge connector.

As for the ROM 3 error, if the voltage is set to around 5.1v at the ROMs and you still get the error, you should try to replace the bad ROM. Cranking the voltage up will damage other chips.

RJ

I set my power supply to a save level and I am reading 5.08v at pin 28 and reading .025v at pin 14 so the voltages at the chips seems to be at the correct levels.  Doing this has brought back the rom error 3 and I have made two videos showing the error:

http://m.youtube.com/index?client=mv-google&desktop_uri=%2F&gl=US&rdm=4owzg9gnw#/watch?v=Wzl5iq5IFsI (http://m.youtube.com/index?client=mv-google&desktop_uri=%2F&gl=US&rdm=4owzg9gnw#/watch?v=Wzl5iq5IFsI)

 http://m.youtube.com/index?client=mv-google&desktop_uri=%2F&gl=US&rdm=4owzg9gnw#/watch?v=MEJ0ViHmeSw

It seems the machine is locking up at a certain point everytime making me think that I do have to replace the eproms but what would cause the chips to work at the wrong voltage but not work at the right voltage?  Wouldn't it be the case that if it was just corrupted programming it would crash regardless of voltage?

Is there someone who offers a rom replacement service or would I be better off biting the bullet and buying my own uv light and programmer?

Thanks.

I do PROM/EPROM programming as a service. Simply order the EPROMs and the programming SKUs off my website. Seth at HobbyROMs also does them.

At this point if it were my game I'd open the top on the power supply (with the game unplugged!!!!) and check the tops of the electrolytic caps in the output section to see if any have split their tops open. If they have, replace them and try it again. Poor power can cause these types of errors and it's easier/cheaper to check that first than after replacing chips.

RJ

So I cracked open the Double Dragon power supply and found this ...

Needless to say I think I'm going to be ordering a new power supply tonight.

I don't see anything wrong with it really...  :103-
All the caps look happy...

... I'm confused... all of that stuff around the base of the capacitors can't be a good thing... also the power supply makes random wizzes and pops which can't be good either.

Oh, I thought it was the non-conductive gooey stuff they put on the bottom
to sort of glue the caps to the board.
The sounds it makes isn't good though...unless you're shooting a commercial
for a cereal that needs "Snap, Crackle, and Pop!"  :5-

That's glue under the caps and not the caps leaking... they look ok from a physical standpoint... they haven't split open their tops or blown out the rubber plugs in their bases. I wouldn't worry with replacing the power supply.

I just submitted a service request message through ArcadeComponents.com, so sorry for repeating some of this;

I purchased a Neo Geo cabinet recently, and it has never had working sound.  I'm guessing it will need a cap-kit installed.

I purchased a Metal Slug 4 cart since owning the cabinet, and the game freezes moments in to the game.  I have cleaned all the contacts, as well as the slots, which doesn't seem to be any help.  I have also cleared the back-up RAM, and run a RAM test by turning on all the hard dips, and the screen said "WORK RAM TEST" the entire time.  I ran the test for approximately 20 minutes.  Are you aware of any other potential causes for this? Should I also update the bios? is there a chance of bad RAM even though the system seemed to handle the RAM test fine?  To clarify, there is no error message, the screen and sprites just freeze in place.

3rd problem, and unrelated to the board itself;

The screen adjustment board has a broken nob on it, probably from someone bumping into it when they were reaching into the cabinet.  I have attached photos for reference.  Is there any hope of a replacement / fix?  I have done some searching, and haven't found anyone selling any.  Is it possible to repair this sort of nob? It is currently very delicate so I don't dare mess with it, but the screen is a bit wide and I'd like to be able to adjust it as well as contrast.

Any advice or suggestions are greatly appreciated.

No problem repeating here... I'm behind on emails thanks to a hugely important project going on at the day job.

That broken pot will need to be replaced. You can find replacements at http://www.mouser.com but since I don't work on monitors I can't tell you exactly which part you need.

Look at the component and look for numbers printed on it. They will be something like "102" or "503"... which will tell you the value of the item in ohms. 102 is 10 followed by 2 more zeros, or 1000 ohms. 503 will be 50 followed by 3 more zeros or 50000 ohms. Once you find the value you want to look at the trim pots (potentiometers) at Mouser. Pay close attention to the data sheets for the parts as they have the sizes and pin spacings listed. This is important as you want something that will fit in the hole spacings on the board.

For the cartridge you need to clean the edge connectors with a pink pencil eraser, clean all the dust off well, reassmble the cartridge and test. Beyond that, check for broken solder joints or bad traces around the Program ROMs. If you had a UniBIOS chip in your Neo Geo you could use it to test the checksums of the ROMs to see if any are bad. Without that the only way to really tell if one of the program ROMs is bad would be to desolder each, read them, and compare their checksums with known dumps from MAME.

Raymond

Thank you for the quick response.

I have cleaned the contacts on the cart with an eraser, but no luck sadly.  I have tested ~12 other carts and all work fine in the system, though they are all older titles.  What are the chances it could have to do with the system and not the game at this point?  Just trying to see what my odds are through process of elimination.  The game's PCBs look fine, almost pristine compared to some of my older carts.

I don't know enough to be sure where the problem originates, and am greatly appreciative of your knowledge about these systems.  Thanks for taking the time to respond even while you're busy with your day job, and I look forward to hearing back from you when you're available to install a cap kit / remote battery.  Would it be realistic to send the cart with the system while you're servicing it, in order to detect the issue?  Or would this be more time consuming than it's worth? (sorry for my naivety about the repair time required, I know this can be tedious time consuming work).

Small update:

I purchased a copy of Metal Slug 3, which is having the same problem as Metal Slug 4.  A few moments into the game the system freezes, with no errors showing.

I am able to run the following games fine on the system:

Art of Fighting
Fatal Fury
Samurai Showdown 2
NAM 1975
Magical Drop 2
Puzzle de Pon
3 Count Bout
Top Players Golf
League Bowling
Baseball Stars Professional
Magician Lord
Ninja Combat
Aero Fighters 2

But for some reason Metal Slug 3 and 4 have the same symptom, which makes me suspicious of the board.  Does this info mean anything to you?

EDIT: After talking to the folks over at neo-geo.com, it sounds like my board is having a bank error; http://www.neo-geo.com/forums/showthread.php?234072-Metal-Slug-4-freezes-without-showing-errors

In the example given, the person did see an error screen.  My only concern is that my screen stays frozen.  Otherwise it sounds like a very similar problem.

Hmmm...

The only thing that comes to mind is possibly a broken or gouged trace on the board. Look VERY closely at the board for any kind of liquid spill damage or corrosion and check for gouged traces.

Hi, I'm from Brazil and I've trying to find a problem on my MVS MV1FZ without success.
The image is shaking a little like some sync problem, using the grid test I noticed that when removed the red and green signals the image is almost perfect and each add a different "noise" in the image.
I've checked the power supply, connections and cables and nothing.
Did have any clue? Anything would be welcome :D
I'm using a LCD screen (tried CRT also) with a RGB to VGA converter/scaler.
Thanks, in advance.

Try it with a standard arcade monitor.

The Neo Geo boards are not quite synced the way many TVs or upscalers can handle. The frequency is off just a tad and the outputs are very strong to the point of overdriving many different display devices.

You might ping some of the folks on the neo-geo.com forums as they have much more experience using upscalers and different monitors/TVs. I'm strictly dealing with arcade monitors as displays.

Thanks, for your help. You're right the problem was the scaler, working fine with arcade monitor.

Hello, do you have the pinout for the Q-sound board in CPS-1 games?

A friend of mine gave me a Punisher board for repairs, since it had committed suicide. However, he did not have the case, only the plain boards. I connected it using just the JAMMA pinout and it was indeed dead. After I followed the instructions for both batteries, and the game booted and became fully playable it still had no sound. The C-board battery was still alive and working, but I removed it anyway since it would eventually fail. Hence, I believe everything works alright. From pictures I've seen online, http://www.flickr.com/photos/54304922@N05/5799243918/in/photostream/lightbox/ there is a connector inside the case of these boards that plugs into the Q-Sound board and the JAMMA out into a single JAMMA connector, and my guess is that I need to build one of these for it to work.

Do you have the pinout for that board? Or should it work without it and I have a fault Q-Sound board?

No, sorry. I do not.

Thanks =)

Hi,
I have been playing with an MV1FZS board for a few weeks on and off that has a flashing graphic pattern and the 'click of death'. I have checked all traces around the work ram and backup ram and actually done continuity checks from each pin to its destination ok. So it doesn't appear to be damaged traces anywhere, I have also con checked the address and data lines as far as possible with no faults found. However I thought the /ce and /oe lines were ok but on rechecking I find that the /oe is constant logic high. I traced this to the SP1 and replaced it from a spare working board. Any further tips ?
Cheers,
Ray

Do you have a way of testing a Power Drift pcb and is there another Sega driving/racing game pcb that will work in a Power Drift cabinet?

No, sorry. It's not a JAMMA board and I don't have the necessary wiring harness adapters.

You sure you traced /CE and /OE properly? I'd have to go back and check a board but those are controlled by the chips in the battery backed section - the 74HC32 comes to mind. Those boards suffer from problems in the battery backup section when the battery starts leaking.

Thanks for the response, I will go and check them again. This is one of those few boards that has no corrosion anywhere near the battery (or under it) however U13 (74ls32) is showing some pitting around and under it, but again tracing tracks appears fine. I will double check the /oe and /ce lines. :)

Hello Everyone,

I am new to the forums, just started collecting some old machines. I am having issues with this Neo Geo MV4F I got though.

Getting the following error:

Video Ram Error

Address
00000E17

Write
5555

Read
D555

Can you guys help point me in the right direction for chip replacement? Also will need to buy these chips and probably replace the original battery too on it.

Thanks in advance,

TimeWarpGamer

This will be one of the 2 surface mount SRAM chips tied to the LCPC chip... Don't recall which one and don't have a 4F on the bench to check at the moment.

Raymond

Ok great,

I think it is these two The cxk5814 chips are the fast video ram? I might just replace them both and see what happens, I have a bad feeling this will bring up the next error on the board but will see.

Thanks - Raymond, if any other tips pop up feel free to post them!

10-4 back to trouble shooting...

No, that would give you an error at $00008000. This is the surface mount chips tied to that video controller

You need these: http://www.arcadecomponents.com/catalog/item/2251646/4758714.htm

RJ

Sweetness -

Thank so much, just ordered them up on your site and a cap kit. Thanks again for the help and have a great weekend -

hello channelmaniac,

i come to you because i know you are an ref from cps1 repair .

i Have an final fight cps1 with cosmetic glitch (A-Board have trouble) ,the B and C board are tested on an other A Bord and it work.

(http://i31.servimg.com/u/f31/13/71/05/61/imgp2513.jpg) (http://www.servimg.com/image_preview.php?i=34&u=13710561)

(http://i31.servimg.com/u/f31/13/71/05/61/imgp2514.jpg) (http://www.servimg.com/image_preview.php?i=35&u=13710561)
 
(http://i31.servimg.com/u/f31/13/71/05/61/imgp2515.jpg) (http://www.servimg.com/image_preview.php?i=36&u=13710561)


Have you some idear of my probléme please ?

Check for the usual things: gouged traces, damaged pins in the connectors where the B board plugs in, and corrosion damage from liquid spills.

Beyond that you're most likely looking at a bad custom chip and needing a replacement A board.

thanks for your reply ;)

i have cheked Check for  damaged pins in the connectors  and corrosion damage from liquid spills and i find nothing of this .

i have a mutlimétre and logic probe can i make other test ?

you have an idea of ​​how the deportation the A-Board for making test easy ?

It's most likely going to be a problem with the custom chip which means you'll need to source a replacement A board.

i'm curse it is very hard to find in France alone :(

Hello Channelmaniac,

I just found out about you and your work and... wow.

I have a problem with my AES. All it does is produce graphic garbage.

I posted photos here if you could take a look :

http://www.gamoover.net/Forums/index.php?topic=26556.0 (http://www.gamoover.net/Forums/index.php?topic=26556.0)

At the top are pics with no game inserted, below are pics with a cartridge in (i get either those blocky stuff or a black screen). Looks pretty serious...

At the bottom of the page are hi res pics of the board (2 sides). (I cleaned everything but nothing changed)

I have no technical knowledge so I shipped it to a fellow neo geo french fan who is currently trying various stuff on it but he's telling me it's avery tough nut to crack ! ;)

Any idea that comes to mind? Any help would be greatly appreciated.

Sorry, but I cannot view the pics without registering on that forum. :(

Can you attach them here?

Raymond

Sorry I forgot about that.

So first here is what i get with no game : (randomly)

Very modern art or something

Secondly, what i get 25% of the time with a game (otherwise just black)

And finally the best pics i could get of the pcb :

the front :

and back :

Check the area around the cartridge slot for trace damage. After that, check continuity on data/address lines between the work RAM and the CPU. If that is all good, replace the work RAM.

Raymond

thanks, we'll try that.

Also, check pins on the LSPC chip for bridged solder and other problems as it looks like that chip has been replaced. In the pic it looks like there's something on pins 100-105.

The work RAM is the RAM chips next to the 68000 CPU.

RJ

Hey Experts,

I have a NEO-MVH Slot1B (the smallest one I believe).  Lots of SMT.

It's dead.  No video, no audio, and apart from one trace leading from the crystal circuit, no clock.

No damage around battery, and I've run over the boards with a magnifying glass and a fibreglass pencil but averything looks fine.

Can you offer any clues as to what might be causing this?

Check the clock pin on the 68K, and check the sync output on the JAMMA edge connector.

I know this might be way too late in the thread, but better to have it documented. A few pages ago I asked for teh pinout on CPS 1.5 games, teh ones with QSound. I got hold of another such board, and documented it at: http://wiki.arcades.mx/index.php/Capcom_CPS#Pinout_de_CPS_1.5

Thanks for sharing the link!

Hello,

I got an MV-4F with some graphical and cart detection problems.
I've read some repair logs here (and there) but it seems I don't have the same board revision.

The board doesn't detect cart in slot 1 and there are vertical lines on the Neo•Geo logo and some in-game graphics (it seems to be on sprites only).
The sound is powerful and clear.
No traces under the battery which wasn't leaking.
Connectors and everything else were cleaned.
There was some kind of oxidation on pins of the NEO-253 chip located in B5 on the top board. I tried to clean that as much as I could and remelted the solders.

I don't really know where to start with those proprietary NEO chips and where to look for each of the two problems.

So if you have any ideas or suggestions, thanks in advance :)

Tools I have at my disposal : digital multimeter, solder station and hot air station.

Some pics :
(http://jomay.free.fr/MV-4F/01.jpg)(http://jomay.free.fr/MV-4F/02.jpg)(http://jomay.free.fr/MV-4F/03.jpg)(http://jomay.free.fr/MV-4F/04.jpg)(http://jomay.free.fr/MV-4F/05.jpg)(http://jomay.free.fr/MV-4F/06.jpg)(http://jomay.free.fr/MV-4F/07.jpg)(http://jomay.free.fr/MV-4F/08.jpg)(http://jomay.free.fr/MV-4F/09.jpg)(http://jomay.free.fr/MV-4F/10.jpg)

PS : I've just found a repair log, from you channelmaniac, about this board, so it's the newer revision and seems to be a bitch ;)
Anyway I will take a look and see if it can help me.

Check the address and data lines for the program ROMs on the slot that isn't recognizing the cart. You have signal not making it from the cart to the chipset chip or not making it between chipset chips.

It is most likely a bad trace and it's VERY uncommon for the chipset chips to go out.

Thank you for your reply.

To narrow my research or not, are every NEO chips connected to every slots (I would say it's logically that way) or are they assigned to one slot ?

It has been a long time... If memory is correct, they each service a slot and they all tie together on their outputs to go to the connectors to go down to the bottom board. That's how the MV4 works.

(http://www.toomanygames.com/misc/pics/neo.jpg)

Hello, I own a 6-slot. It played ok, but it was very dirty. After cleaning it, there are some vertical lines visible.
All slots and all games give the same problem, after looking around on the web I found several documents with all the same text. Wich lead all to here i think.
Now is my problem is it says to check pin 4 for output, but in the datasheet its pin 5 as output. Or do i overlook something?

When in doubt, trust the datasheet. I'm only human. ;)

Hey Channelmaniac,

I wanted to send you some Neo Geo Boards to fix up for me. I have your repair form, but what is the address to send these to?

Thanks and Happy New Year!

PM me here, on the KLOV forums, or on the Neo-Geo forums.

Since I work a day job, I don't post my address online. If I did, I'd be buried in boards!

Raymond

Hello Channelmaniac
I already posted my problem and I've tried to fix it, folowing your instructions: http://newlifegames.net/nlg/index.php?topic=152.msg881#msg881 (http://newlifegames.net/nlg/index.php?topic=152.msg881#msg881)
but I got confused.
Al signals on input and output seem fine with the logic probe. But when i tried to find the bad chip by shorting pin 15 and 16. But there is no chip that doesn't make extra lines appear. There is one that changes the look of the problem line so I thought I found the bad chip, but if i let the game play and put it on pause again the lines move to another location and there is another chip that changes the look of the line?
Here is some pictures i found in the thread which look the same as my screen: (I'm not able to make useable  pictures myself )
(http://jomay.free.fr/MV-4F/07.jpg)(http://jomay.free.fr/MV-4F/10.jpg)
But on the pictures i found online you can't see if the lines move along with the graphics. On Pulstar for instance all moving graphics seem to have similar issues. Only static and text is fine.
The connection between the top and bottom board are fine. The 6 first (A1-3 and B1-3) and 6 last are shorted together, but I think this is supposed so (GND and +5V?)
Is there anything a can still check?
Thanks in advance

Dumb question: Did you clean the slots and the cartridges?

If so, how?

There are no dumb questions. I did clean the slots and the cartridges, I used alcohol and cotonbuds. But strange thing is all cartridges give the same result in all slots. The symptoms look identical withe the same cartridge in slot 1 to 6. So I don't think the problem is slot related.
But do the lines you describe in your original cure move along with the graphics or do they stay on the same place?

Open the carts and clean the edge contacts with a pink pencil eraser. Q-Tips and alcohol will not remove the surface oxidation from the edge connectors and you will still have poor contact with the slots.

Also, fold over some poster board a couple of times until it is as thick as the cartridge board, lightly wet it with alcohol and insert/remove from the slot a few times. You'll see gunk come out of the slots.

Once you have it cleaned well you will be able to see if it's really a problem with the top board or the carts. ;)

Raymond

Hi, I did clean the carts and slots. The contacts of the carts are nice and shiny now. The slots are hard to see if they are shiny, but there was some dirt coming out. I renewed the poster board until it stayed clean. But this didn't bring any solution.
My problem occurred after taking appart the 2 boards for battery exchange and cleaning. This cleaning I did by rinsing the boards with water and letting them dry for a few days. (I cleaned 100's pcb's that way as a daytime job some 20 years ago, without any problems?)

But can you please tell me if the lines you describe in your instructions move or don't?

If you turn Dip 8 on to freeze the system, the lines shouldn't move. If the graphics are moving then the lines will appear to move too.

At this point you should check the outputs of the graphics ROMs on the cart and follow the signals down from the cart to the inputs of the chips on the top board. Then check from the outputs of those chips over to the connectors that send the signals down to the bottom board.

The 4 slot and 6 slot systems use 74LS245 chips or x-to-1 data selectors to latch the various ROM outputs from the selected slot to the connector going to the bottom board. The outputs of those 74LS245 latches for the Program ROMs are tied together and go to the connector. The outputs of the x-to-1 data selectors aren't tied together but all go to another connector to go to the bottom board. Check the outputs of those chips to see if you have one that is racing or stuck high. Check the inputs to see if one is racing or is missing a signal. Check the connector to see if one pin is missing a signal.

For missing signals I use a well calibrated finger on the logic probe tip. This little trick causes bad gates or open logic lines to go crazy when you touch the probe tip to the pin. It allows you to see an instant change on the screen when you touch a pin that is floating with no signal on it or if you touch a pin that has a failure on the inside of the chip.

Thanks for your quick response, :131-
OK, if dip8 is on the lines don't move.
But I only tested the 74f251 chips for signals. Are those the x-to-1 data selectors you talk about?
As you described in http://newlifegames.net/nlg/index.php?topic=152.msg881#msg881
They all got signal in- and output. The logic probe I use doesn't light up when floating. So I'm pretty sure there are signals, all give busy, none stuck. I have only one cart plugged in so the signal is coming from the right cart. I also checked the input selection pins and they all give the right bit result.
You say the outputs can be racing? What does that mean? English is not my native language, sorry for that.
I'm now checking connections between the 74f251 chips and the connectors to the lower board, but I don't think there are any bad connections because there turn up new lines if I connect the input to high.
What I get confused about is, if I find the chip that alters the appearance of the lines by taking the input to high and I let the game continue by flipping dip8. Then I put the same input of the same chip on high and there pops up another line along with the problem line?
So I think the problem is further down the line. Where are those signals going to, ones they are on the lower board?
As this is a graphic related problem there is no need to check the 74LS245 and 74LS244 I think?

Follow the outputs of the chips to the connectors leading to the bottom board. Check for continuity from the chips, through the connectors, down to the bottom board. I had one board on the bench once that had junk inside the connector causing a fault.

Also, look at the bottom side of the bottom board for gouged/scratched traces.

Racing means the output is oscillating and outputting junk.

I already checked all pin's on all four connectors on the board. All give good continuity top to bottom. Didn't look further on the bottom board so far. The six first an last seem to be all connected together but i think this is OK (maybe GND and +5V?)
To night I check for continuity further on the bottom board.
Is there any way to check the output signal on racing? With a logic probe I can only see if it's busy i think?

When you see a racing signal, you will know it by ear, if your logic probe has audio output. If it doesn't, the only real way to see it is with an oscilloscope.

Is it safe/usefull to connect the input pin to the output pin of a suspicious chip?
Or pull the output down to look for change?
My logic probe does not have a audio output, and I dont have a scope.

Sometimes... Depends on if there's a hard short to power or ground.


That's the easier way. Do it momentarily.


Ouch. This makes it hard. The audio output on the probe makes it much easier to compare the input signal to the output signal on the chip. I *HIGHLY* recommend you get a logic probe with audio capabilities.

Still confused. Sorry, but every time I try to look for the faulty chip an other one seems to be bad.
If I flip dip8 to pause and start pulling up input signals a different chip alters the appearance of the line. The chip that seemed faulty in previous tests only add another line. Also if I ad a line by puling up an input those lines look different than the one whose always there?
I try to test continuity of all tracks but it takes quite some time. And I think there isn't a problem as with all 32 27F251's lines change or appear on the screen.
The only thing I suspect is the IC in the SFIX IC-foot.(it says 381000-20, 7C6 BK, 9035 Z01) The SC1 and SC feet are empty? Then the tracks go to the SNK PRO CT0 chip.

The FIX chip is a mask ROM - 23C1000. You can read it with some EPROM programmers and compare the checksum to the checksums found in MAME.

There are 2 empty ROM sockets on the Neo Geo 4/6 slot boards. That is normal. Beyond that, you may have a chipset issue and that's as far as I can help you now.

Can you please explain what you do mean by "a chipset issue"? Then I won't take any more of your time for now.

Chipset issue means a problem with one of the custom chips.

Great repair logs, I've enjoyed reading through them!

I did not run across mention of the issue I'm having with a Capcom 1943 board set, so I figured I would ask here.

I have a 1943 with glitchy sprite graphics(scrolling background and character text is fine), but from the service menu the roms all check out ok. Near the object rom chips on the B-board is an IC that looks fried, a Capcom 86S100 28pin dip. Inspection of the board underside reveals a nice scorch area directly under the chip. Being a custom Capcom IC, I have had no luck finding any sources for purchase. Have you had to replace one of these chips before on a pre-CPS1 Capcom board? Side Arms & Tiger Heli also use this particular IC, so I am on the lookout for a donor board, but am hoping out there on the Internets these chips might still be floating around.

Thanks!
Aaron

I have a few parts boards... will check and see if I have the component.

Never seen one of those fry... the problems I've had were with the big PLCC custom so I should have a board in the junk pile with one of those dead PLCCs.

RJ

Thanks RJ, that would be awesome if you had a spare I could purchase from you. The chip is part # 9C if I remember on the Video/Sound B board.

I have some. You have a PM.

I did some probing on the suspect 86S100 chip with my scope, and the chip is still alive but acting erratically compared to the other two chips of the same type on the B-board. Shorting pins 5 & 6 improved the display, but still left "jail bars" through all the enemy/player sprites. 5 & 6 are supposed to connected according to the schematic, but for one reason or another related to the chip fault were not. Looking forward to replacing the chip and seeing if this board is back to 100%.

I removed the existing chip yesterday, not an easy job with the tightly packed footprint of that particular 28pin dip, and the very low profile of the package. I'm just using a solder sucker however and a little patience. Good thing you had one on hand, I'm not sure I could have removed one from a donor board without frying the chip in the process. Easier I'm guessing with a vacuum setup? Expensive tools, but I might have to look at one if I get serious about repair work.

Night and day difference.

Having a good desoldering station will just flat out amaze you. :)

What brands would you recommend? I've had good luck with sub-$100 Xytronic and Weller solder stations, but am not familiar with their more specialized products.

I use Pace gear. Hakko is good too.

I have an interesting Issue with a couple of boards and am looking for pointers.

One is a Kuri Kinton, it looks pristine but when playing the game, or in demo mode, there is no collision detection that produces damage. The enemies can't hit the main character neither the enemies can be hit. They cannot go through each other though. The same happens in the demo mode. I've already checked the program roms, and burnt all alternate sets form mame with no changes, and also played with all the dip switches.

I've scoped around it and have found no evident cause.


The other is a Side Arms. Some sprites are shown incorrectly, they are made up of the same half twice. I have been testing it slowly, and noticed that one of the data lines had noise, specially after some time and one mask rom was heating fast. Replaced three mask roms that had that pin apparently burnt... they could not be read, and they caused noise in the line. They are normal now after replacing them with suitable eproms However, I am still looking for the half sprite issue.

My guess is that a it must be wrong that causes some multiplexing for the sprite data... any other ideas? will continue checking it.

Thanks!

Wow... not sure on the collision detection. That's something that is different on every boardset. If it's a surface mount boardset then I'd start with reflowing any custom chips.

On the double graphics issue, check the address lines for missing or stuck signals on the graphics ROMs and graphics RAMs.

I just received a Neo Geo 6 slot and it doesn't boot to the crosshatch screen. My monitor just displays red blocks.Please Help.
Photos:

http://i1272.photobucket.com/albums/y397/misschivousyoo/IMAG0063_zpsba6be8a5.jpg
http://i1272.photobucket.com/albums/y397/misschivousyoo/IMAG0058_zps9c7ea632.jpg
http://i1272.photobucket.com/albums/y397/misschivousyoo/IMAG0060_zps60dafe93.jpg
http://i1272.photobucket.com/albums/y397/misschivousyoo/IMAG0065_zpsa779516a.jpg
http://i1272.photobucket.com/albums/y397/misschivousyoo/IMAG0066_zpsc2a442cb.jpg
http://i1272.photobucket.com/albums/y397/misschivousyoo/IMAG0062_zps542d7de0.jpg
http://i1272.photobucket.com/albums/y397/misschivousyoo/IMAG0056_zpse7531ebf.jpg

Hmmm... Looks like the CPU isn't starting at all. Check the power then the /CE and /OE lines on the backup RAM for missing signals. (These are the RAMs connected to the CPU, but are powered by the backup battery circuitry.)

Most likely culprits: Bad BIOS, bad Backup or Work RAM, missing control signals on the Backup RAM (see above), corrosion damage from a leaking battery (causes control signals to be missing on Backup RAM), or a gouged trace somewhere.

Raymond

I picked up a Capcom CPS1 Mercs board for cheap as "untested". Powered up fine, but there appeared to be palette issues, as the backgrounds were two tone (just black and white) and the game sprites had weird colors. Checking the color bar test in the service menu showed only muted beige and grays instead of the usual r,g,b.

The graphics all seemed intact, just with palette problems, so I assumed the ROMS might be fine and swapped out the A board with one from a working Magic Sword set. Game powered back up fine! So the issue is somewhere on the A board, but I'm not sure where to start. Any recomendations for graphic related A board chips to take a look at?

That's a difficult boardset to work on. I've found that generally it's the fault of the large surface mount custom logic chip. :(

You can check the pallette RAM by replacement... but that's really about it.

Thanks for the reply, it does not sound very promising for salvaging the A board.

Schematics appear to be very hard to come by for the CPS1 board set, so I have not been able to locate the palette ram. I did switch out the 5 socketed 20pin dips on the A board (they appear to be PLA chips), but no luck. The board had some rust and corrosion on a number of proms on the top layer (A board looked better), I wonder if reflowing the graphics chip might catch a bad joint that I'm not seeing with my magnifying loop. Can't do any harm I guess, so I might give that a try after I've located the palette ram.

Who's yer daddy? :)

http://arcarc.xmission.com/PDF_Arcade_Manuals_and_Schematics/Forgotten%20Worlds%20%28Capcom%29%20CPS%20Schematics.pdf (http://arcarc.xmission.com/PDF_Arcade_Manuals_and_Schematics/Forgotten%20Worlds%20%28Capcom%29%20CPS%20Schematics.pdf)

Thanks for the link! That was a rhetorical question right? ;)

I received the 1943 chips today, and had a chance to solder one in tonight. Unfortunately, the new chip behaves the same as the previous one did with pins 5&6 shorted. So although I don't have to short pins 5&6 on the new chip anymore to fix the sprite palette issues, there was no additional improvement to the pulsating jail bar pattern on the game sprites (except for bullets and the player sprites which are fine).

So out of luck in that location I followed the action downstream and decided to investigate a blue Krylon wire that connected two pins on two different D-type dual flip flop ICs (74s). Without the connection, the clock pin of the 2A flip flop is floating, and the result is no graphic sprites of any kind (just backgrounds and text). I was scratching my head until I googled 1943 pcbs and discovered that all the images I could find had this same blue wire. So it wasn't evidence of an early repair as I had thought, but perhaps patch work done at the factory?

Last thing I tried tonight was piggybacking a pin compatible 74 onto the 4-5 Flip Flops in the same area on the board. No change however with the sprite jail bars.

So at this point there is the big graphics chip that might be the culprit after all, unless I can come up with something else.  :8-

Yeah, that big one is a pesky problem :(

If the TTL/LS chips are shorted, piggybacking won't show that. You'll have to replace them to find out if they were the problem.

Raymond

In the process, I have learned a couple interesting things about the 1943 board set. I found a picture of a B board with three small daughter boards instead of the three custom chips you sent me. The boards had Capcom labeling and model numbers, so maybe the early 1943 releases didn't have the custom chips yet. I also found that connecting the 2A clock pin to a pin 32 on that big graphics chip would pause the game. Could be a handy feature since 1943 has so many stages!

My buddy and I purchased a set of Indy 500 racing games and it worked perfect at the guys house.

BUT...

When we got the machines back to his house the Fiber Optic system that is hooked to the coinbox is missing, we called the guy we bought it from and he said he doesn't have it and we didn't leave it behind ( :37- DON'T ASK...we are still looking for it :103-).

Do you know if that piece is replacable and if so where? or if there is a way to bypass that coinbox and plug the machines directly into each other?

Thanks

Tim

The fiber optic cables are simple Toslink cables and you can get them at Radio Shack, Fry's, and other places.

Do you know if I can bypass the coin box inputs and plug directly to and from machine?

You should be able to. I think those are just cables from the board to a jack to make it easier to get to.

I found the time to check all connections from the 27ls251, via the boardconnectors, all the way down to the grafix chip on the bottom board. If you like I can post my findings in a table for others to use?
But all tracks are continuous.
While I was looking at the bottom with my 20x watch repair eyeglasses to find some damage to other tracks, I spotted 2 small holes in the backup battery? As the problem started after putting that battery in, I should have seen this earlyer! But before I soldered in the battery I checked the space and it was fine if I trimmed the ic-legs. But the battery wasn't fully flat down after soldering as I see now. So I pushed the battery down and checked again for space. Now its OK.
Put the 2 boards together again and tested. Works like a charm.
Seems to be my logic probe isn't up for the job, as I didn't find the error while checking the shorted pins.
After this I found on http://www.arcadecomponents.com that the the type of battery I used doesn't fit in a 6-slot board and I found out the hard way.

PM me the info on the connections and I'll post it in my SNK thread, or you can post in the NLG Users' Repair Logs section.

Congrats on getting it fixed!

Yes, on the 4 slot boards there are no chips above the battery on the top board. With the 6 slot board there is a chip above it which will poke through the insulation on the battery and short it out. :(

It's best to use an off-board NiCd or NiMH battery on those... or a CR2032 lithium coin cell conversion. Just make sure you neuter the charging circuit before using the coin cell or it will leak or rupture.

Update on my ongoing 1943 saga...

I picked up another "not working" 1943 boardset last week. This one had a missing 8751 PROM (security chip) on the A board, so I was hoping the B board was good to replace the B board in my original set. So I pulled the 8751 from my first boardset and used the chip to replace the missing PROM, and fired up the new boardset to test. And surprise, the new boardset fired up and had the same graphic glitches that my original 1943 had. I also have a bootleg 1943 set, which doesn't use the 8751 at all, so I hooked the bootleg A board up to the B boards from my other sets, and confirmed that both B boards worked just fine! So it seems the issue with my original board is a bad 8751, or both A boards just happen to have the exact same graphic glitches.

Being a security chip, I'm guessing the 8751 has not been dumped, but I need to check the MAME romset. ** Checked the dump list, and as of Feb, the 8751 for 1943 has not been "decapped" and dumped. So now I'm in the hunt for two working 8751 chips, to get both board sets working.

Since the bootleg A/ Capcom B gave me a working game, I tried an experiment to fix the English translation on the bootleg by swapping the BM04 EPROM for a Capcom BM04. Rather then fix the translations though, the PROM swap switched the game to Japanese! So I guess the bootleg is really a Japanese 1943 with English "dubbing" from the BM04 PROM. So I have now a working Japanese version of 1943, but the only catch is the sound from the bootleg A board is rough, like it isn't being mixed properly (sound effects are loud and crackle, music sounds fine but is low in volume).

The journey continues...

Crazy!

Not sure if I have any of the 8751 chips from the 1943 boards. I think all the boards in my big pile o'scrap are other Capcom boards and not 1943. :(

On the sound issue, the first thing to do would be to recap the audio section.

Graphic problem NEO MVH SLOT4FS

I have a 4 slot neo geo, one of the "new" 4FS type.

In a video on my youtube you can see what I mean. I can't explain what is on the screen. There is no audio on the video, but this is because I turned the volume down.

http://www.youtube.com/watch?v=wacvY-23Q2A (http://www.youtube.com/watch?v=wacvY-23Q2A)

Where do I start to fix this. I tried finding broken tracks but can't find any. The slots are cleaned well and all slots give the same problem. The cart is OK, it runs well on my other 4 and 6 slots. But the other 4slot is of an older type so I cant switch top and bottom boards.

Anny suggestions?

Start by cleaning the slots, looking for gouged traces on the top of the top board and bottom of the bottom board. Look for liquid spills or rodent damage around the chips on the top board which will result in trace damage. Next, check the address and data lines going to the cartridge slot for missing signals.

Thanks channelmaniac, I found 2 broken traces really close to the IC pins. The pins had turned green by some mouse pee. The board was full of pee and droppings when I bought it.

Just another question. Along with the board i got a ctrg of Top Hunter. It also needed allot of cleaning. I took it appart, cleaned the contacts with an eraser as you told me before. After this the game didn't play well, so I re-soldered the whole board. Now it plays but there is no sound. Also, if i put it in my multy-boards, ones it comes by, all games lose sound. I tried it on my 2 four slotters and on my 6 six slotters all with the same result. Is there any way to fix this?

Regards.

Check the traces going to the M1 ROM, especially around the mounting holes in the board. If they are all good, replace the ROM.

Update of my ongoing 1943 repair saga...

Finally got around to recapping the sound section of the bootleg A board I am using, and now the music volume is back to the right level. The sound effects still sound a little distorted and loud, but the sound quality in general is much improved. Not knowing if the bootleg sound was just poorly mixed to begin with, I'm at a point where I think I can live with the boardset at 90% versus putting anymore time into it. If I come across a working legit A board for 1943 I'll swap it out in a heartbeat, but otherwise I think this repair saga has come to an end!

If you have an oscilloscope you can check the op amps to see if one is bad.

I do have a scope (a basic BK 2120) so I'll look for op amp chips in that section and check them out.

I recently splurged and picked up a Hako 808 for desoldering. What a difference, night and day versus a solder pump! I followed your advice on soldering smd chips as well, but instead of fixing bridged pins with solder braid used a quick shot with the Hako. The chip barely felt hot to the touch when I was done. I never thought I'd be able to solder up a 28pin TSSOP at home, but it worked like a charm!

I wipe the tip of the iron clean, put a little rosin flux on the pins, and use the iron to draw off the solder bridges. Works like a champ, especially on the super tiny pins that you can't get close enough to with the desoldering iron tip.

RJ

All traces  of the M1 ROM test OK. So i think the ROM is bad. Do you sell these in your on line shop? And do you ship to Europe?

Yes, but shipping is very expensive now to Europe. :(

Which ROM is that - a 27C010 or 27C301?

How do I know what ROM it is?

Here is a picture (its not mine but it's just the same, I used it to compare jumpers)
http://mvs.gotwalls.com/images/e/e3/Top_hunter_set1_b2_front.jpg (http://mvs.gotwalls.com/images/e/e3/Top_hunter_set1_b2_front.jpg)

What would be the shipping cost?

Not 100% sure... but since it has 32 pins available for it, but is only a 28 pin chip, and is 1 1Mb ROM, I'd say it's a 23C1000 OTP ROM which you'd need to replace with a 27C301.

Raymond

I checked the Rom on the far left of the board, the one with M1 printed below. That's a 32 pin chip, the one with S1 underneath is one with 28 pins. Is this the one I need to replace/check?

Check the pinouts of the ROM and try to determine which is A16 and which is /OE to determine if it's a 27C301 or 27C010. Probably will be a 27C301.

4 slot the crosshatch problem.
took out the battery, wasn't leaking. Checked the traces near it anyways, all OK.
Checked the 74f138. The enable inputs get High Low High instead of Low Low High for single use as explained in the datasheet. Is this normal if the carts are not recognized?

Regards

Check them while the board is booting to see if you have activity while it cycles through the slots.

However, you're better off checking for damaged traces/chips on the address lines and data lines on the cart slots.

Back with another interesting board issue...

I recently picked up a Final Fight pcb with major graphics issues (the screen was split into fourths, and mixed up). I swapped out the A board for a known working A, and that problem cleared up.

However, now I have a character pattern across the screen that stays constant no matter what game screen I am on (including the test menu).

ROMs all check out OK on post. I've reseated the C board, checked the B/A board connectors, and reseated all the ROMs on the B board as well.

Could this be a problem with the C board smd chip?

I attached a screenshot of the display, covered in 'y' characters.

Fixed!

Turns out I missed a ROM on the B board that had a bent under pin.

My guess is the last person who looked at the boardset tried reseating the B board ROMS to fix the graphical glitches caused by the bad A board. In the process they curled up a pin on the 05 ROM. I straightened out the pin, fired the game up and good as new! (when paired with a donor A board of course)

I found a nice tool for straightening pins, a pair of eye glasses pliers. The inside surface of the jaws are flat and smooth, so they work great for straightening out pins, or bring a whole row of pins flush.

Nice fix!

I use a miniature pair of duck bill pliers. Look for a pair that have smooth jaws that meet perfectly. Grind the jaws down on the outside so that the tips will fit in between pins of the chip and you can use them to straighten individual pins from side to side and three pins at a time in a row.

Raymond

Hey channelmaniac, I've got a neo geo 4 slot that isnt producing any sound. the caps look replaced but the HA130001 looks like it was poorly repaired. could you help me out with some repair work?

Drop me an email at my user id at yahoo

Hey Channelmanic, my adventures in board repair continue...

I just fixed the graphics on a Black Tiger board. The player/enemy sprites were all garbled, and I found that putting pressure on the big square graphics chip cleared up the problem. I knew from reading your repair logs that I should try reflowing the joints, but wasn't sure how to go about it. So what I did was to go pin to pin with my soldering iron and apply a little bit of fresh solder, holding the iron in place until the joint reflowed. Those pins are so close together that a number of times I bridged pins, which was kind of a pain to clear up even with flux and solder braid.

My question is if there is an easier way to reflow those pesky graphics chips that have so many pins? I thought about just laying down a solder coil on each side, and then cleaning up with my Hakko desoldering gun, but the angle is tough to get the nozzle in the right position. Curious what would be a good technique to leave the reflow work looking nice and clean, for resale purposes.

Liquid rosin flux is your friend!

I use a 1/8" chisel tip, but a conical chisel works best as the dingle oval surface of the tip hold the ball of solder in the best position for the J legs on a PLCC chip. Lay down a thin layer of rosin flux on the pins where they meet the bard, put a small ball of solder on the tip of the iron, hold the board at an angle, and run the tip with the ball of solder down the legs where they meet the board.

The liquid rosin will help the solder flow and keep the solder from bridging. If you have bridges, simply use a bit more rosin flux and use a clean iron tip to draw the excess solder away.

Thanks for the tips! I didn't know rosin flux was available in a liquid form, I have a tub of the sticky stuff.

The other problem that Black Tiger board had was no sound. I checked out the twin Yamaha sound chips, and matching op amps, and the outputs were dancing along as expected. Went I took the probe of my oscilliscope and ran it over the amp pins to see if I could get any static on the speaker, the sound suddenly came to life. Shorting pins 8 & 9 on the amp fully restored the sound. I'm not sure why that worked, the traces on both side looked good so that didn't seem to repair an existing connection that was broken. Board is working great now, so I'm not complaining :)

Probably a bad cap that you zapped. :)

I use this: http://www.onlinecomponents.com/gc-electronics-104202.html?p=11386794

It's a good brand of flux.

Thanks for the link, I will give that stuff a try!

So I think I understand what you are saying about the cap. A bad cap was potentially killing the audio signal, but when I ran my probe over the amp pins I might have shorted it? I guess I should probably track that cap down and replace it, although the audio still sounds good as is.

Just wanted to say thanks for writing up the CPS-1 audio repair guide that can be found in various places online. I picked up a SF II Championship Edition board set with no sound.

The YM3012 IC was not outputting audio, and the clock signal on pin 6 of the Z80 was ok. A couple of the Z80 data lines I checked though looked dead. Replaced the Z80 and fired the board back up, and sound was restored :)

I pulled the replacement chip from another A board with bad graphics, so it was not a Z80A like you have mentioned in your repair logs. I socketed the chip though, so at least if this one goes bad, it will be easy to replace!

More adventures in repair land! I fixed a few boards since my last post, but now I've ran into a game that has me stumped.

Sky Shark from Taito. Powers up to black screen, nothing on the rgb or sync lines, and no audio. I tested the program roms (17 & 18) and they were good. With the board dead, I started at the CPU (68000). RESET & HALT are high, and there is a CLK signal that looks correct (8mhz). The address & data lines have activity, but the RW pin is stuck high (Read mode). A few of the address lines are low (A10-A12), while the rest have signals. A1-A13 are connected to a 8x8 64KB SRAM (HM6264LP), which is connected to EPROM 18 (program rom). I traced A1-A13 to the SRAM, and then to the corresponding pins on EPROM 18, and all the signals match (including the low value for A10-A12). I'm still suspicious of the low address lines, but also not sure if I'm barking up a tree without any cats so to speak.

Also interesting I found all three interrupt lines on the 68000 were stuck high.

Thinking the CPU might be dead, I pulled and socketed a new replacement with the exact same results.

So now I'm a bit stumped, any help or advice appreciated!

What does the reset line do on power up?

Good question, I had not thought to check!

I hooked up a logic analyzer and watched the reset line and a few of the address lines during boot. The reset line goes low for about 60ms, and that is followed by the address lines springing to life shortly after. 60ms sounds about right for a 68k, based on your "Reset lines & CPUs" post that mentioned a minimum period of 50ms.

I was hoping not to find that reset pulse there, that would have been a good lead.

Check Address Decoding to see if the control lines for the program ROMs and Work RAM are working. If they aren't, you know where to check. If they are, replace the Work RAM.

A MC68000 CPU problem?
I've got a Demons World board which is dead. Black screen and no audio (appart from a click when turned on)
Took a look at the reset en hold lines of the CPU, they are OK. Clock is present, but there is no activity on the addres lines, does this mean the CPU is dead?

Hard to say. What is the halt line doing and Bus Error?

You really need a storage oscilloscope or logic analyzer to tell for sure. Could be a bad CPU or could be that the CPU is trying to start but address decoding isn't working right for it to read the ROMs. The bus could be coming up and stopping faster than your logic probe will show.

I took some time to look into it further.
My cheap  storage oscilloscope tels me the reset and halt line is kept low for 280 mS. During this time address lines are high. When reset and halt go high, the address lines get busy for about 35 mS and then go high.
You ask about the Bus Error? Is this the BERR* pin? This looks the same as the address lines. So i think the CPU is OK?
I took out the Rom's and read them out, my programmer doesn't get problems reading them, so i think they are OK. Where to look now?

If no schematic is available, you'll have to trace each address line, and maybe data line. They are probably multiplexed to different TTLs, to select between several chips. And the data might go into a 74LS244 or 74LS245. You'll have to check those and figure out which one is not responding.

Before that, I'd check if the data lines do get busy as well, if they don't and the CPU is reading, then you know it is probably the data bus.

Yup... Artemio has it.

If your data bus is working then check after any 74LS244 buffers on the address lines and any 74LS245 latches on the data lines. If those inputs and outputs look OK then check address decoding to see if the ROMs are being accessed properly.

I checked all pins and this is what i came up with:

VCC 4.72V

Address lines:
A1 ON RESET 4.18V ACTIVE STOP 0.48V
A2 ON RESET 4.18V ACTIVE STOP 4.06V
A3 ON RESET 4.18V ACTIVE STOP 4.06V
A4 ON RESET 1.33V ACTIVE STOP 4.06V
A5 ON RESET 1.33V ACTIVE STOP 4.06V
A6 ON RESET 1.33V ACTIVE STOP 3.89V
A7 ON RESET 1.33V ACTIVE STOP 3.89V
A8 ON RESET 1.33V ACTIVE STOP 3.89V
A9 ON RESET 1.33V ACTIVE STOP 3.89V
A10 ON RESET 1.33V ACTIVE STOP 3.89V
A11 ON RESET 4.18V ACTIVE STOP 3.89V
A12 ON RESET 1.33V ACTIVE STOP 3.89V
A13 ON RESET 1.33V ACTIVE STOP 3.89V
A14 ON RESET 1.33V ACTIVE STOP 3.89V
A15 ON RESET 1.33V ACTIVE STOP 3.89V
A16 ON RESET 0V NOT ACTIVE STOP 3.89V
A17 ON RESET 0V NOT ACTIVE STOP 3.89V
A18 ON RESET 0V NOT ACTIVE STOP 3.89V
A19 ON RESET 0V NOT ACTIVE STOP 3.89V
A20 ON RESET 1.39V NOT ACTIVE STOP 3.89V
A21 ON RESET 1.39V NOT ACTIVE STOP 3.89V
A22 ON RESET 1.39V ACTIVE STOP 0V
A23 ON RESET 1.39V ACTIVE STOP 3.89V


Data lines:
D0 ON RESET 0V NOT ACTIVE STOP 0V
D1 ON RESET 1.14V ACTIVE STOP 0V
D2 ON RESET 1.32V ACTIVE STOP 2.63V
D3 ON RESET 1.17V ACTIVE STOP 0V
D4 ON RESET 1.17V NOT ACTIVE STOP 0V
D5 ON RESET 0V NOT ACTIVE STOP 0V
D6 ON RESET 0V ACTIVE STOP 0V
D7 ON RESET 4.62V ACTIVE STOP 0V
D8 ON RESET 4.28V ACTIVE STOP 4.02V
D9 ON RESET 4.56V ACTIVE STOP 4.34V
D10 ON RESET 4.56V ACTIVE STOP 4.34V
D11 ON RESET 4.56V ACTIVE STOP 1.71V
D12 ON RESET 4.56V ACTIVE STOP 0.81V
D13 ON RESET 4.56V ACTIVE STOP 3.72V
D14 ON RESET 4.56V ACTIVE STOP 2.06V
D15 ON RESET 4.56V ACTIVE STOP 1.78V


Other signals:
AS* ON RESET 1.52V ACTIVE STOP 0V
UDS* ON RESET 4.66V ACTIVE STOP 0V
LDS* ON RESET 4.62V ACTIVE STOP 0.46V
R/W* ON RESET 4.56V ACTIVE STOP 0.44V
DTACK* ON RESET 4.08V ACTIVE STOP 4.08V
BG* ON RESET 4.08V NOT ACTIVE STOP 4.08V
BGACK* ON RESET 4.08V NOT ACTIVE STOP 4.08V
BR* ON RESET 3.8V NOT ACTIVE STOP 3.8V
CLK 10MHz
HALT* ON RESET 0V 280mS STOP 4.66V
RESET* ON RESET 0V 280mS STOP 4.66V
VMA* ON RESET 0V NOT ACTIVE STOP 4.02V
E BLOCK SIGNAL 2.5MHz
VPA* ON RESET 4.2V NOT ACTIVE STOP 4.2V
BERR* ON RESET 4.7V NOT ACTIVE STOP 4.7V (NOT AS REPORTED BEFORE)
IPL2* ON RESET 3.4V ACTIVE STOP 3.4V
IPL1* ON RESET 4.7V NOT ACTIVE STOP 4.7V
IPL0* ON RESET 4.7V NOT ACTIVE STOP 4.7V
FC2 ON RESET 1.15V NOT ACTIVE STOP 3.84V
FC1 ON RESET 1.15V ACTIVE STOP 0V
FC0 ON RESET 1.15V ACTIVE STOP 4.2V

There was no activity on the D0 line and 0v so i checked this. Seems the pin gets grounded some where on the board. Its not easy to trace the line to other components as it dispears  beneath several IC's. So I cut the line near the CPU. (maybe I committed a sacrilege, but I'm only trying to save this board from the junk pile.) Now it's not grounded so the shortage isn't inside the CPU. If I measure the pin on start-up there is nothing happening on that pin it seems to be floating? This also happens with the D1 pin after "disconnecting", if I feed the line from D1 into the D0 pin it looks happy and gets some activity :)
Now I think I need to find the shortage somewhere on the board, also for the D5 pin. Or does the lack of activity on A16-21tell us there is allot more going on?

You need to trace out where the connection goes and find the bad component. The CPU will never boot with the data bus being in a bad state.

I spend some time tying to follow the tracks that are grounded, but its hard because if I try to beep where the track reapears, I often find an other ground. While tracking my eye caught one chip with 2 burned pins, its a smd with allot op pins, it says nec D65024GF035, and I cant find any info about it. One burned pin goes to +5v and the other GND. On to of the chip is a small bump so I think there's some internal damage.
This means the end for my repair attempt.

Yup. Sounds like the chip is toast.

Can you post a close-up picture of the chip?

Here's the picture you asked for:
(http://farm4.staticflickr.com/3790/11822836523_32c672908f_z.jpg)

The bump I first noticed is below the "P" of JAPAN, now I also see a large crack between the two burned pins.

In full: Link   http://farm4.staticflickr.com/3790/11822836523_765190589d_o.jpg (http://farm4.staticflickr.com/3790/11822836523_765190589d_o.jpg)

BTW thanks for your support,  :131-

Yeah, that one is toast for sure. I see 2 cracks in the top of it too.

I did some digging and all I see are Chinese suppliers but no data on the chip.

Hello Channelmaniac. Long time listener, first time caller here.

I had a Street Fighter 2 Hyper Fighting board that I sold to a gentleman on another forum. When I tested the board in my test cabinet before posting it for sale, I was sure the sound worked. The gentleman, being an avid SF fan, says that not all the sounds work properly. Here is his quote:

"Only part of the music and sound effects are coming through while other parts do not, even when volume is turned up and down both on the pcb and on the cab. Sort of like an orchestra is playing with half the instruments missing."

I'm wandering if this is a few bad roms or, from what I've read on a few of your fixes, the Z80? I've never come across a board that had some audio not working. Any help would be appreciated. Thanks.

Shouldn't be the Z80. If that were out you'd have no sound at all.

Look for gouged traces on the bottom of the A board and the top of the B board around the 3 ROMs for sound. 1 of them is the Sound Program ROM and 2 are for sound effects that play via the OKI sound chips.

Try to determine if the music is playing and the sound effects are missing. if so, check those 2 effects ROMs to see if they are bad.

Next on the list of possibilities would be incorrect sound program ROM or sound effects ROMs. So many of these boards and ROMs get swapped around by people that it's possible that they are mismatched sets.

If they check OK in an EPROM programmer and the traces are good then I'd recap the sound section on the A board. Those caps rarely ever go bad so I'd check the other items first.