The problem I have is the game wasn't always seeing the balls in the batcave. So I started going through the diagnostics and using the pinwiki. When I do the row test check of disconnecting connectors CN8 and CN10 and run a jumper from CN8 to CN10 with a diode I find an issue. From pins 7 and 9 on CN8 and going to pins 3,5 and 6 on CN10 it usually doesn't show a closed switch. Works fine on all the other pins. And I can go from all the other CN8 pins to CN10 3,5 and 6 and get switch closures. So while I see this I'm not sure where the problem lies. The logic probe tells me all these pins on CN8 have pulses, and CN10 has highs. I would appreciate a little help here.

Still trying to figure this out if you can help.

Well it isn't just my jumper setup since the same thing happens during play, and also in test mode. It is very repeatable with the same three switch positions giving the same intermittent problem (although mostly they don't register). Without having any missed triggers when I use a column or row. I reflowed the solder on the connector. I don't have an oscilloscope, so I guess I'll read some voltages.

Can't be the switch positioning since it happens without the connectors to the switches.

Finally got back to this. Still happening, but I have more info. When I jumper it and fire a switch, they usually fire instantly. But from CN8P7 pins 3,5,6 on CN10 don't register. But from CN8P9 pins 3,5,6 on CN10 will register, but I have to make contact for about a second. From the other pins they are all instant. But from CNP4 CN10P1 is also slow to respond.

Measuring voltages they all look the same except CN8P5 which is 3.8v versus 4.32 on the rest. The voltage at the top of R101 is .8 volts and the rest are at .49v. So while they aren't all the same, it doesn't seem to make sense to me.

Nothing looks corroded. Continuity seems great. Resistances look good. Didn't see any shorting capacitors when I checked continuity. 6821 is soldered in so I couldn't reseat it.