Where do I start with this rat's nest?

[The Expanding Man]

I bought a cheapish Astro City from ebay sight unseen. Turns out, it's had a very hard life, and looks like it has had some pretty dodgy maintenance over the years.

It was working perfectly. Now, I am getting no vision at all from the monitor.

It looks like the wire from the Jamma pin-6 12v dc power has come loose from whatever it was wired to.

This cab appears to have been rewired a few times over the years. Cables change colour as they progress, as cables have been soldered together and wrapped in insulation tape.

I cannot reliably work out where this cable has come loose from.

Any suggestions as to where to start?

Pics:

[burgerkingdiamond]

I bought a cheapish Astro City from ebay sight unseen. Turns out, it's had a very hard life, and looks like it has had some pretty dodgy maintenance over the years.

It was working perfectly. Now, I am getting no vision at all from the monitor.

It looks like the wire from the Jamma pin-6 12v dc power has come loose from whatever it was wired to.

This cab appears to have been rewired a few times over the years. Cables change colour as they progress, as cables have been soldered together and wrapped in insulation tape.

I cannot reliably work out where this cable has come loose from.

Any suggestions as to where to start?

Pics:

if you've got some experience with soldering and re-wiring I would just say scrap it all, and get a new JAMMA loom and find a pinout online. It's not complicated. You have your buttons, speakers, power input, and video.

[emphatic]

I would get completely new wiring for the control panel. Player 1 harness: http://triplemoonstar.brinkster.net/the ... ockid=2037 (3 buttons)
Player 2 harness: http://triplemoonstar.brinkster.net/the ... ockid=2038 (3 buttons)

Buttons 4, 5 and 6 for both players: http://triplemoonstar.brinkster.net/the ... ockid=1471 (buttons

Also, sign up at ArcadeOtaku.com as it's a forum dedicated to candy cabinets. You will get expert help there for sure.

[dpful]

the 12v wire only goes to two places, from the power supply to the jamma connector, and from the power supply to little lights on the cab (like a light bulb on the coin slot on american cabs). How it connects to the power supply is-- either the power supply is labeled or you've got to use a multimeter and see which terminal puts out the 12v. It shouldn't have anything to do with the monitor. if the gameboard isn't getting 12v, it might not work at all (the 12v usually just runs the sound amp on the board.)

It would be nice to rewire the cab, just to keep track of everything, but you wouldn't have to if you could just follow every wire and check for probs.
These three sections:

5v-> pcb
-5v->pcb (sometimes)
12v->pcb and sometimes little lights ...grounds on all these from pcb power section back to power supply

all switches... jamma harnes to proper switch, all switches common ground back to jamma harnes ground.

video, RGB ground sync,... from jamma harness to monitor properly. (this ground is coincidentally the same as the buttons and joysticks ground) (it's the same as the power ground also, but you usually keep those seperate since the power ground has 12v on it too and might want a thicker wire. all the rest runs on 5v.)

If there's a mechanical coin counter in the cab, it's wired like a button from the pcb, plus has power going to it also.
the wall voltage from the cab goes here:
120v (240?) --- wall to power supply, overhead light (if the cab has one), monitor (through a isolation transformer first sometimes). usually interupted safety switches on all the access panels.

[Dave_K.]

I had a similar rat's nest and decided on gutting the entire cab to clean it out, replace the CP wiring, and fix the original jamma/power supply wiring (too difficult to find replacement for that). I also have the original manual with wiring schematics, so that helped. I'm sure its on the net somewhere, but all I could find was the New Astro City manual.

Before:





And after: