Quoted from statictrance:Is there anyone in the US that services Zaccaria MPU boards (or does anyone have a guide to do some basic troubleshooting)? I have a clean one without battery damage that isn't booting to a game. I've never worked on a zaccaria before, but I'm not finding a solid guide for MPU2 and unfortunately don't have a Zacc in house to test with for anything lower level.
The customer claims it was 'just working'... I clipped the battery but don't see any physical damage. I do see one chip with 'bad' written on it - but it's a 2101 that's in the display circuit, so even if that ends up being bad, I'm doubting it would keep the board from booting. Anything thoughts? (Game is a Farfalla, BTW)
I recently went through and rebuilt a couple MPU 2 boards for Devil Riders. Both working now except that one (the one that had battery damage) still has an issue interacting with the sound card. Just need to make time to track that down.
Definitely verify the ROM images to make sure that they are ok and haven't degraded. If those are bad the board won't boot. As far as I remember the 2101 is written to by the CPU (but can't read from it) and the contents are just used for the displays. Unless it is bad in a way that is pulling up or down one of the address or data lines preventing the code from running. That chip should be socketed. If so pull and test.
I also ran into bad RAM on the board used for the main part of the game. That kept it from coming up. On my one clean board I installed a 4F memory capacitor so no need to get NVRAM or off board battery. So far it is working well.
If you get stuck I may be able to repair it for you. Just need to wrap up some existing repairs first.