Hello,
I have been roped into fixing my friends Pinball machine.
It is 6502-based, has 2 RAM chips (not sure what they are but they're about the physical size of a 6116), 2 PROMs, 3 6532s and a battery backed 5101 RAM for factory settings and hi scores.
The PROMs are socketed but everything else is soldered.
I'm going to CRC check the PROMs first, and assuming they are OK, the next step is to pull the 6502, solder in a socket and get my Fluke 9010A on it. (As shown here
http://artsarcadegames.com/fluke_9010.htm)
I can test ROMs and RAMs easily, and my hunch says that it's a RAM problem (often is with old arcade games) but I've never tested a board with 6532s before. Do these often fail? Can anyone tell me how they occupy the address space or point me at a datasheet?
If one of these is blown, is there much chance of it stiffing the rest of the CPU system by holding a line high or something?
What I'm really trying to do is get this fixed with as few visits to my friends place as possible as it's right in the centre of London, and thus be armed with knowledge. Fixing pinball PCBs is awkward as they are at the top of the machine and have lots of connectors on them!
Thanks,