Mat Mania/Exciting Hour Schematic?

[GAJoe]

I recently acquired a Mat Mania board that's not working right.  I get garbled game sprites all over the screen, usually in the same pattern, every time I start it up.  I've cleaned and reseated all the chips, and I verified all the ROMs against the MAME versions, and now I'd like to get down to tracing the circuit through to find the problem, but I can't seem to find a schematic for the board.  Does anyone know where I can buy or borrow one?

Additionally, does anyone have experience working on Mat Mania/Exciting Hour/Mania Challenge?  I know I could just as easily buy a new board for 20 bucks, but I really want to learn from trying to get this one working.  I'm hopeful that, so long as the problem isn't with one of the processors, I can fix this myself.  I was thinking I might next try replacing the few electrolytic caps on the board, though none of them look to have bulged.  Any thoughts or suggestions on what to do next would be appreciated, and I'd definitely be thankful to have a schematic of the board so I wouldn't be working blind.

[GAJoe]

I've still got this board sitting on my bench collecting dust.  All I get are garbled graphics of people at ringside.  I've checked all the ROMs against the MAME versions and they all match.  I can try randomly troubleshooting sections of the board, but without a schematic I'm just grasping in the dark.  I have the manuals for both Mat Mania/Exciting Hour and Mania Challenge, but all they give me is the wiring diagram for the harness.  I really need a full schematic.  Does anyone know where I can get one for this board?