Jennings J400 help

[dummkopf]

Hi,
I just picked up my first slot, a Jennings J400 this weekend at a farm auction of all places!  The cord was bad so I bought it as-is.  I replaced the cord and tried to see if this thing would work - but the only thing that works are the fluorescent lights in the door.  No segment display, no bells or whistles.  The three fuses I found look ok.  The battery is missing and looks like it corroded at some  point but not too bad.  I reseated connectors, etc. with no luck.  Can anyone give me some guidance on what to check?  I have experience with arcade games and am no stranger to a meter and iron.  Thanks!

[ROCKET]

 
Pictures are what we always ask for ..the more info we always ask for ..

any other details you want to toss in would be great ..  even what you have worked on before etc 
so we all have a idea of what skills you start with .. all questions i asked are for a positive result 
 --none meant to insult you . any other good deals at the barn sale ??
Rocket .

[dummkopf]

Some pictures...

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I tried to attach more pictures, but they won't upload.  I'll have to try and scale them down and then try again...

My background - I am an embedded software engineer - and I do a lot of prototyping for the companies that I do work for.  I am not an EE, but I can read a schematic and get myself some hardware to develop on way before I have real hardware.

I have several arcade games that have needed various repairs over the years, mostly re-capping monitor chassis and power supply work.  The Galaga needs some trim-pots replaced as the adjustments are shaky.  I have an EPROM programmer as I have had to replace some PROMs that have had corroded legs on them.

The auction was mostly farm equipment, but there was some random stuff.  I bought two crank telephones as well to add to the collection...

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Any other pictures that would be helpful?

[ROCKET]

Any other pictures that would be helpful?

not from my point of view --that solder side picture of the main board picture #  965.6 ?
that rates on the top "10" looking worst looking repaired boards i have seen in years ..
WOW!! THE FINGERS ON THE EDGE CONNECTOR ARE NOT EVEN THERE IN SPOTS ..

I cant tell you where to start or even attempt to want to start .or find parts to save that board if the rest inside electronics looks the same ?and it does within reason . make a lamp out of it ..

[dummkopf]

The first thing I would like to do is probe for power.  Any advice where to start with that?  Are replacement main boards available?  I agree, that's a lot of 30 gauge wire under there...

[ROCKET]

Then find the power supply where its fed from wall outlet. Then take a multi meter or voltmeter and check for power once its plugged in and your hands are not in a spot to get Zapped. As far as boards. Start googling for boards. Your not going to find one from Jennings I can say that with 100 percent certanty. As far as the rest of it. What I was trying to say without insulting you is the other electronic boards look as deteriorated as the ones in pictures. It gets to a point is it worth fixing. To track down parts for a old dog like that. Its cheaper to find one in working order if you have your heart set on that particular machine. Good luck on the venture. 

[ramegoom]

I have recently gone through four of these machines (two just like yours, two with the topper - 700 series). The logic boards were all pretty similar, with extensive acid damage to the boards, but all were salvageable. The problems I found were mostly connection problems. You need to take the shelf out and get to the back plane board. I had some acid leaching on one of my machines that got to the connectors on the backplane, so I had to replace the corroded connectors. That solved the problem. Also, most of them had bad connectors on the hopper (they kind of float and self-align). Replace them and all is well. Also, I had some leaky TRIAC's on the backplane, had to replace maybe 6 total between four machines.

The edge connector on the logic board can be repaired by grafting new fingers onto the board surface. Those NiCads must've been a big problem with the Jennings machines! You can run the game without the battery, as there is a capacitor that can be placed on the board to eliminate the battery. And, those jumpers under the board are put there from the factory, and have to do with how many lines, and how many coins the machines take. I'll post a few images of the variations I have between the four machines.

I would go through the board with a bristle brush and try to eliminate the acid from the board. The problem is when the acid gets under the IC's, which traps it. You can remove the IC's closest to the acid damage, clean the board VERY WELL, and then place a socket on the board. The chips are mostly available, some are CMOS and some are TTL. The CMOS section of the board is isolated by a diode, which is the part of the board that the battery normally keeps alive. I did a repair using a cordless phone battery in place of the factory NiCad, but it's probably better to install the cap fix:

[ramegoom]

Check for power on the terminal strips behind the hopper. Here is what you should find. Also, the fuses should be 2, 3, and 4 amps respectively.
http://www.jenningsslots.com/Jennings%20Images/Transformer%20Wiring.jpg

[dummkopf]

ramegoom - thanks for the replies,  I need to get the slot up to my lab where I can work on it better and then I will start on your suggestions.  I'll keep you posted.

One question that I have - where did you purchase the parts (connectors, ICs, etc)?  Do you have part numbers that you can share?

Thanks,
Tom

[ramegoom]

Most of the parts you need are available at www.mouser.com
The connectors on the hopper: PN 538-38330-0508 for the female plug, 538-38330-0108 for the male plug. You need to remove the alignment pin on your original male connector and install it into the new connector, and drill the mating hole out of the female connector with a 5/32" drill (first, remove the terminal - and hold the part in a vise).

The IC's and transistors are pretty much obsolete, but you can find equivalents all over the internet; try www.marcospecialties.com and "The Real Bob Roberts" site for old chips. The IC's are mostly TTL with some of them being CMOS TTL. Use a pencil eraser on the gold edge fingers of the logic card, and if you see any corrosion there, take the machine apart and look at the edge board receptacles. Any corrosion there, replace them, again, available at Mouser.

Most of what's inside that machine can be sourced and replaced. With a little luck, the logic board is OK, and you can always send it to www.jenningsslots.com for overhaul (and peace of mind).

[dummkopf]

Here are the results from the power probing:
On the TB-2 terminal block from right to left what should be +5V, 12V, and 24V DC.  I have a solid 5.0V, 14.44V and 14.80V DC.
What would this point to with the bad voltages?

Thanks,
Tom

[ramegoom]

Either a bad power supply, or a bad connection to the power supply. Four hex nuts and a connector, and the power supply is out of the machine. I would inspect the connector as it could have picked up corrosion. Also look at the gold edge terminals on the PC board.

Also check to be sure all of the connections to the transformer are intact.

[ramegoom]

Any updates on your project? The machine looks pretty clean, so I would imagine it won't be too much longer to get it going.

[dummkopf]

Well - I found a gentleman on the board that spun his own redesigned logic board with a microprocessor instead of all that cmos logic.  I haven't received it yet.  As far as the power supply, the same guy recommended that I deep-six the linear supply for a switcher.  I'm still researching switching power supplies and looking for a pinout for the supply connector in the slot machine.  I'm hoping that I can make a fingerboard to interface between that connector and the linear supply so I don't have to cut any wires.  Has anyone done this?

[ramegoom]

Haven't done it but I think it's a good idea, and there is room for a switcher in the back of the cabinet. I have one slot to go, and it's got a power supply issue, haven't delved into it yet.

I believe there are 3 different voltages to address; 5V 12V and 24V. I'd have to look into the current requirements for each output and see if a single switcher supply is available. There might be an IGT supply that will work.

The good news is, you would eliminate that transformer. Switchers are direct 120V in, so you could have some extra room for possibly a stand-alone 24V switcher, and a regular (miniature) computer power supply would work for the 5 and 12 volt sources.

[dummkopf]

I was wondering about that transformer - I didn't know what it was used for, if it was for isolation only, what it was feeding: DC power supply, AC loads like the fluorescent lights in the door...

[ramegoom]

Pretty sure the transformer is only for the electronics. The fluorescent lights are 120V AC.
Here is a 24 volt supply I found: 
http://www.mpja.com/24-Volt-Desktop-Power-Supply-265A/productinfo/18509%20PS/

And for the 5 and 12 volt sources, look at these:
http://www.mpja.com/33V-16A-and-5V-14A-and-12V-15A-EOS-Power-Supply/productinfo/18090%20PS/
and
http://www.mpja.com/5V-3A-and-12V-2A-and-5V-350mA-Artesyn-Power-Supply/productinfo/17721%20PS/

Starting point anyway.

[dummkopf]

Ok quick update -  I wired up my new switchers and am ready to connect the dc outputs to the rail.  Before I do that, I want to verify that the rightmost post on the rail is ground (labeled 05 in the diagram)...

Ill post pictures when it's all hooked up!