Nothing quite SUX like an incorrect schematic, damn they can cost you days of labour because thigns don't match up, then you're led to tracing tracks.....yuk!!!
...of course if you get rid of your pin2k machine, then the problem is gone ;-) 
MM.
It's not mine Marty. I have been working on this one board that is a shocker, not only has it had dead I.C.s it also had one that was changing the voltage on the data lines, the warmer it got the higher the voltage on the data lines got (between 2 & 4.5 volts
)and when it was cooled down the data line voltage dropped. Not that the I.C got hot to touch or anything.
It made for some interesting intermittent faults, such as when the coin door was open for a while the switch matrix would register it as closed and enabled all the so called high voltage circuits. then when in attract mode it would randomly start the game without pressing the start button. The strangest thing was that the faulty chip was one of the ones that monitor the fuse circuits and had nothing to do with the dedicated switches.(the start button and door switch are on dedicated switch inputs for those of you who didn't know.)
