Monitor works (I think) but no picture?!?

[vocalninja]

I had a working jamma cab last week. Everything on it was working fine until I connected a pcb with the jamma harness upside down.

I smelt something cooking so I quickly disconnected it all but the power supply had fried. The monitor still works and shows a grey screen and I can still adjust all the settings (brightness etc...)

I bought a new power supply and plugged it in with a new game pcb. The new PSU lights up green but there is still no picture to the monitor. The screen does come on though grey with scan lines.

I'm about to jump off a bridge right now because theres nothing left in my life.

The monitor still works but did I fry something else last week? Any hints would be welcome and I wanted to know what else can happen when jamma is connected the wrong way.   

[SirPeale]

You fried your board when you put current thru where it doesn't belong.

[Ken Layton]

Yeh it sounds like yor gameboard is shot now. You probably did extensive damage to it.

[vocalninja]

I tried a new multigame game pcb but that doesnt work either.

Do coin boxes blow up as well because when my machine starts up, the coin unit doesnt make a noise on startup like it used to before this tragedy.

I've put in a new powersupply and new game pcb but no luck. I'm starting to guess something in the jamma circuit has gone pop but I suspect its the coin unit. I could be wrong.

Do I need to check for continuity on the harness???

[grantspain]

sounds like you ain't got the psu wired up correct
when you swap a psu you must check your voltages go to the correct pins on the edge connector using a pinout guide and a multimeter