HERE it is!! My Bally JACKPOT ONLY machine.

[Amechanic]

Mark..

 Here is a picture of what each PS loops voltage is.

Gary

[shortrackskater]

 My meter shows 4.97, 6.94, zero which is the ground, and 9.63.
  I think my power supply is working.

[Amechanic]

It’s working but not great. Those numbers are a bit low but hopefully will do for now. Did you pull the power supply and look it over for bad solder joints?

[shortrackskater]

Yes and I re-soldered one voltage regulator that just had a crappy job. By the looks of the board, It's been replaced along with the big cap I think. I think the next step is the connector but what are the two wires that Barry mentioned?

"Also the bottom 2 wires/connection usually go bad."

[Amechanic]

Bottom two wires on the plug.

[Badbaud]

Also check the power supply board header.

Clean it up with a green Scotch pad.

If any copper is showing on any pins (tin gone) the entire header should be replaced.

[shortrackskater]

 So I decided to vacuum some of the “dirt “at the back of the machine, and the dirt and it up being rat droppings, and we all know what that means!
 Here’s a picture of the wiring harness back behind the transformer on the right side. I’m in the process of removing the transformer right now.

[Amechanic]

Surprised it didn’t blow a fuse? It looks like it might be only one or two wires. Post a better pic when you get the transformer out. 4 screws and a couple plugs and it will be out. Mark your plugs with a sharpie.

[shortrackskater]

 It looks like some of the wires in the middle of the bundle just had the insulation eaten off. If you look to the left there’s two  more damaged wires that just stop right there – I can’t see any connecting wires on the right side of the bundle.
 There was also a terminal block just above the harness that had a broken wire –  I fixed that.

[Amechanic]

Looks like to me that you have at least 6 wires damaged or cut. Looks like you have a grey or brown one under the red one. Then the yellow with red on the top.

[shortrackskater]

I'll need to look for a wiring diagram  - I think we have one here on the site, or at least something close.
Wondering where those gray/yellow and gray wire "ends" should go.

[Amechanic]

It’s possible that those two wires were part of a plug that wasn’t used. I’ll have to see if I have a machine I could look at. If you don’t see those two colors on the other side, then I would assume they were a plug.

[shortrackskater]

I patched up the eaten wires and taped off those two loose wires on the right but still don't know where they go or where they went.
I painstakingly re-installed the transformer and connectors, powered up and got nothing. The "6" code was there but when I powered off and on, it disappeared. Maybe the battery is charging now - I'll check, but that part doesn't really matter. And, nothing appears to go to that terminal block either - I'm not sure where those wires went originally.
I'm guessing the next step is to replace that connector on the power supply.

[Amechanic]

Double check your fuses, use a meter. Then power it on and wiggle the power supply plug and see if your display changes.

[shortrackskater]

I did all that, three times. No change. 

[Amechanic]

I wonder if you could have a 5101 ram chip problem? Did you pull them off the ram board and inspect the sockets. Be next to the battery I have had green contacts inside those sockets. You did mention that you had a pin on the ribbon cable that’s questionable. I guess you try a new PS plug.

[shortrackskater]

Ok I pulled the RAM board and cleaned the contacts. I also did a decent repair of the broken pin on the ribbon cable. It was an end wire so I just nipped it off from the connector, stripped the end and added solder to the bare wire. I plugged that into the socket and then plugged in the connector over that and ensured nothing was shorting. (I did find a new old stock 16 pin DIP ribbon cable on eBay for about $10. I don't see them anywhere else but I might post a WTB or contact Alan.)
There's no change. And I still have the "6" in the display. I don't thing that matters at this point anyway.
I think my next step is that p/s connector...

[Amechanic]

I think if you look on EBay, you will see that the ribbon cable, ps plug and battery are all from the same seller. If you bought them all at once you could save on shipping.

[shortrackskater]

I have multiple issues I think here.
I just noticed that there's a blinking light in the reel #2 PC board. And there's what looks like a 1 watt resistor that's hot as hell.
So it seems there's another issue independent off whatever else is going on here.
Should I still start with replacing this P/S connector? I've PM'd Alan - he has all the parts I'd need but I would still like to troubleshoot this a little instead of just replacing everything.
This is getting frustrating when so many multiple issues keep popping up.

[Amechanic]

a blinking LED in the reel #2 PC board.
Should I still start with replacing this P/S connector.

Are you talking about the reel read board on reel 2?? Or some other board?  The plug is going to need to be replace at some time to fix that problem. The led’s on the reader do pulse when power is applied. At that point the resistor on the reel reader board does get hot if left powered on. I’d first work on the 6 code, new plug, if that doesn’t fix the problem, then it’s new ram chips if the voltages check good on the test loops.