Monitor issues? Not sure......

[ZEN]

Hey all, I am working on a Captain America 4 plyr Jamma cab with a 25" WG7131.  When I picked it up it played fine, brought it home it played fine.  Monitor colors were not super vibrant, but decent.  I took the back off to  check some controller connections.  When I went to turn the power switch on at the top of the cab, it stuck midway and I had to wiggle it to continue, it was right after that when I have had problems since.  The monitor powers up, the speaker statics some, some colors pop up, but it looks like horizontal fuzziness at the top of the screen, I see no logos and hear no game.  The board powers as it has an led.

I swapped another known good board in, and virtually the same issues.  The only thing visibly that I could see was one purple wire, appears to be a ground that has pulled out of the chassis (jamma side) harness.  Pic below, but if a ground it looks like its stuck in with the other pin, sorta like a daisy chain.  see below.....

Not sure what else to do about it, or if the wiggling of the power switch damaged the iso transformer, or the filter ets, etc, anyone have a similar problem??  Or an easy fix for this idiot........

[grantspain]

first thing you need to do is check the voltages with a multimeter

[SirPeale]

Does it play blind?  IE you coin it up and hit P1 start and hear noises?

Oh, how about a closer shot of the connector area and the loose wire.   It's just too far away.

[Kevin Mullins]

The monitor powers up, the speaker statics some, some colors pop up, but it looks like horizontal fuzziness at the top of the screen, I see no logos and hear no game.  The board powers as it has an led.

I'd check power supply voltages leading to the JAMMA harness as mentioned.

Pinout for the wire that came loose, you should have:

1 Red
2 Green
3 Blue
4 Ground on either 4 on the large section or 1 on the small section
5
6

1 Ground (optional, see above)
2
3 -Horiz Sync