Hey all, I'm hoping someone can help me troubleshoot an issue with my ToM. I'm new at fixing these things, maybe this sounds familiar to you all.
My game operated totally perfectly, that is, until I messed with it. One of the speakers was scratchy, probably just aged, so I performed the speaker surgery project in Tony's Do-It-Yourself guide (here: http://www.dziedzic.us/wpc_speaker_replacement.html ). I did this to become acquainted with the machine a bit, because this is my first pinball machine. I don't THINK that's the cause of my recent troubles.
I also was curious about ColorDMD (I'm still not sure how I feel about it, honestly, I think I like it better with the original DMD), but while doing the speaker upgrade I also installed the ColorDMD to see what it looked like. Lesson from this: Don't do two mods at once. If something breaks, you don't really know what was the cause.
Unfortunately, after performing all this surgery, I now have some intermittent weird problems. When the game is going gangbusters, and a lot is going on simultaneously (like Multiball or various game modes), the game will freeze. The DMD will literally lock on whatever frame is on it, the lights of the entire playfield will turn off, and SOMETIMES the game will reboot. Other times, the game won't come back from a power cycle, the CPU hanging in blanking state.
When the game doesn't come back from the power cycle, I can sometimes bring it back to life by removing all the ribbon cables from the CPU board and adding them back one by one, bottom to top, turning on the machine each time. When I remove all the cables, the CPU board boots normally. I add the first, restart it, no problem, and continue up the board. I've found that when I add back the cables, sometimes when I add the cable (upper left on the CPU board) that connects both to the sound interface board and the display board, the CPU board goes back to blanking state. If I remove it, it boots, with errors (obviously no display). Monkeying around will get it back, but then the intermittent issue pops up again and I start all over.
Unfortunately, since the cable involved touches both the sound AND the display, I'm having trouble figuring out what might be the cause.
Any thoughts on what I broke? Could the ColorDMD display be drawing too much power or something? My audio engineering knowledge says to me that speakers (and their sizing) shouldn't have an impact on the sound board, so I suspect something else is afoot.