Area 51 Repair Logs
Game board was stuck in watchdog.
Board had been worked on before and was tagged as "unrepairable". One chip that was replaced not soldered well at all. It was like they used silver solder on it and it was VERY difficult to resolder. Resoldered that FPGA chip then the CPU and DSP chips.
Cleaned the PLCC socket on the IC that reads the gun inputs and replaced a bad 14.31818 MHz crystal oscillator.
Replaced the missing hard drive with a 2Gb Compact Flash card and adapter then tested the game.
Symptom: Red/Purple scrambled screen
Board had no output on sync. Replaced a bad 7406 at location C20 to fix sync. A 10 ohm SMT resistor at location R118 was out. This caused the board to have no green output. Replaced the resistor and tested the board.