Still working on an Indiana Jones that I screwed up by plugging in the High Voltage connector for the A/V board into the Driver board J120 out for High Power solenoids. Fixed all but one of the solenoid problems and have posted in another thread the diagnosis, results and repairs required for this royal screw up.
Still have one nagging problem and I'm not sure it's due to my connector snafu, or if this was an issue that's been here all along. The 20V line for the flash lamps measures at only 8.7V DC. And that is with the coin door switch open OR closed. The LED 5 for 20 volts is on, but as soon as I try to start a flasher test, LED 5 Goes out and no flashers will come on. Not surprising given the low voltage on the circuit.
I have checked the voltage at the input at J102 pins 1,2 and 3,4 and its low there too. Only 3.67V AC (Should be 16V AC) direct from the transformer as far as I can tell from the schematics. So I unplugged the transformer completely from the rest of the game and tested ALL the outputs and every single one checks out fine except for 2. The two outputs for the sound board are supposed to be 18V AC and measure at 13V AC. Sound seems perfectly fine in test mode etc., but I wanted to point it out.
The 16 volts for the flash lamp circuit is closer to 17V AC at the transformer plug.
So what would cause this drop to the J102 connector at the driver board?
P.S. I did replace BR4, C11, and checked the fuse for correct rating. I think I replaced it anyway, but it's spec at this point