video corrupt mk2.5

[PHALANAX]

all reels numbers and letters.......reboot holding robot temporarily getting a few images then into all letters and numbers on the reels
the playline numbers showing good...the credit pay etc good but instead of numbers underneath letters....
Has the main door open showing so i dont supposenits a good sign....under credit it reads dbffc...under win it reads ffofffff........under pay it reads....fffc.......last bet reads 55.......I have spare boards ......is it a faulty board or are the gamechips corrupted........Ultimately is it worth a shot transferring the chips to another board ...or will  replacing one of the bords rectify...I have a spare mk2.5 rack and boards is it woth transferring the game chip set........or will i be risking damaging the boards....any comments......
UPDATE...im thinking its a stack error....pulled the robot board its working fine....tested the upper  gamechip board its good as well......ran the lot on another unit it comes up with the same.....will swap the lower gamechip board and see how it goes.....theres no u8 chip on this board Ive checked around and this is how its normally configured....i did manage to get rid of the main door open message.......any ideas......lol...

[SS308]

Needs a ram clear by the sound of it,
see attached doc.

[PHALANAX]

Thanx will give it a go...
OK gave the ram clear a go it did do as the guide but had no effect on the reel display (3 rows of five reels all with rolling letters numbers and micro colour squares...I pulled the character display chips and transplanted them to another charactor board ..it made no difference...I pulled and transplanted the other chips and transplanted them to what i know was a working video processor board...NOW...I have a good top row of 5 reels....a middle row with 2 good outer reels...
and a bottom row with 4 good outer reels......I have credit 18223   win 3951  pay 1  last bet 18
the video processor board i transplanted to looks to have some slight alterations than the original.
the original video processor board has a 08157 assy. whereas the new board ive had partial success with is pcb 40125...  Any ideas on how I might get the remaining reels to picture correctly...lol......im gonna go play with the jumpers and see if that will cause an effect...lol..
 
UPDATE....have concluded the original video processor board is faulty....and that the transplanted board is not compatible... so ive restored the transplanted board to its original game chips and settings and its working perfect ...so no damage done.....Am gonna scource another board of the same type ..until then this lil project goes on hold.....lol...thanx for the ram clear info...

[palindrome]

Have you tried replacing the video ram ?

Should just be a single SRAM chip somewhere on the main board.  Suggested that to someone else who had a similar problem with their MKIV few months back and the change fixed the problem.

Edit: Here is an image of a MK 2.5 main board with the video board removed and showing the location of the video ram.

[PHALANAX]

Ok will check that out.....strange thing is when i swapped the chips from the 08157 board to the 40125 board and removed the link3 jumper near u43 the display acted exactly as from the original 08157 board .ie...letters and numbers.....i havent given up on the original board yet..I have managed to source what may be a suitable board but its on the other side of the planet...lol...not sure why swapping the gamechipset didnt work as the 40125 board is working with its original gamechipset returned....Am however glad the board wasnt damaged by my experimenting.....I sifted a similar problem on the net with a gent that bought a perfectly working machine and stored it for a period  of months and then when he rebooted it acted exactly the same.....
I believe the gamechipset is very similar to his (carribean gold ) but have noted the carribean gold board (with pics) on this very site is even different to the one I have..(it looks very much like the board i swapped all the chips to )The gamechip set I have is Treasure island and just looking at the carribean gold slot glass.. im  thinking that this is the same game albeit possibly a southern hemisphere variant...Cheers for that will give it a go when I get some free time....

[palindrome]

As mentioned in your first post, this sounds more like a stack problem. I just remembered that the chip shown above also holds the the system/stack mem.

Video buffer is from                 0000 - 0x07ff
System/stack mem from           0800 - 0x17ff


Good luck.

[PHALANAX]

Im thinking i may have jumped the gun and overlooked the obvious....being the onboard battery...the working board with good battery i swapped to was not configured for any feature play...thus when i changed the game chipset all but four of the reels displayed correctly....im thinking the reels that didnt display correctly have extra code added to them to enable the feature.... im thinking the only way the guy who had a fully working machine before he stored it would end up with the same is if the onboard battery failed assuming it was securely stored....maybe im getting an overun due to the fact that no memory is being held.......will pull all removable chips from the board and  give the battery a change and see what happens...UPDATE....the bad news is the battery is an old emmerich soldered into the board and as some other posters have discovered all hell can happen after changing a battery.. : (10s or better and others) ..its currently reading 1.18v when it should be 3.6v....so its definately expiring....im almost tempted to wire the replacement to the underside of the board...lol  whilst leaving the original in place but sadly i dont think it will fit into the rack....lol ..might try melting the emmerich plastic cover off and soldering the new battery to the old ones pins whilst leaving the old one in place or buy 2 batteries and solder one to the back of the board and then remove the old battery and solder the new one to the top of the board and remove the one soldered to the back of the board...either way ...i wont be just pulling the old battery out...after some of the drama ive read on this site about what happens when you replace the battery.....loL....will let you know how it goes in a few days .....

[palindrome]

If there was any problem at all in nvram, even 1 bit of difference between any 3 copies then you would get the metering error & a lockup.

[PHALANAX]

Noted...cant do any harm replacing the battery as it is expired anyway...might save some drama later..lol...will get onto the video ram as well.... thanx for your help it is much appreciated ......

[Heihachi_73]

I can replicate this type of error in MAME by simply creating a fake NVRAM file full of 0xFF bytes, but it can still be cleared to factory defaults using the standard reset procedure, ready to coin up afterwards (of course though, MAME doesn't rely on a battery keeping everything intact!).

Corrupt reel graphics after they flash once and FFFFFFFF all over the place and in the menus (the bet of '55' is actually 255 truncated to 2 digits, or 0xFF in hex), usually indicates cleared NVRAM. If the entire chip was entirely full of 0xFF bytes though, the 8-bit RAM checksum would also fail and force a metering error, despite all three copies being identical (of 0xFF bytes).

[PHALANAX]

Ive put this project on the shelf for a while....I have 3 chips that are the same located....u6...u29..u30 and notice the u16 chip looks to have been replaced at some stage
Im not sure changing the u6 chip on its own or all 3 will achieve anything... im gonna wait and see how the other poster does with his chip change...Ive noticed different chips in the same locations on other boards....I might take the lazy option and just wait for a similar board to surface  ....cheers...best i managed to get was all reels showing bar 2 inners on the bottom line and 1 inner second line....credit and pay were showing ridiculous amounts....bet was 18.....lol....Im hoping all good things come to those that wait...lol
ONTO SOMETHING DIFFERENT...ANYONE KNOW ? what the 4 switch mainboard  settings are for Black Rhino......cheers......lol...

Below is a screenshot of what i got doodling away...lol

[PHALANAX]

OK...ok...ok...well well well....managed to get the over-run problemo sorted after numerous very frustrating trials...swapped a few chips here and their and bingo 6 months later video is stable....albeit my next mountain in this epic adventure is sorting the metering error call attendant....I can get the metering interface up but its not via robot....its via reset and collect.....have to take a small vacation before i venture any further...suggestions most welcome......im thinking of threatening it with a plasma cutter....lol....adois friends...its a long way to treasure island ...eye .....mateys....