Pit Fighter Repair Logs

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Repairer: channelmaniac

Symptom: Game controls not working

Replaced bad 74LS244 ICs at locations 70B and 75B. Tested board.

Symptom: Garbled graphics

Swapped IC S30 with a parts board to fix. Burned a replacement GAL for the parts board.

Symptom: No video output

Traced the missing video signal back to the output latches. Signal was on the input side but not crossing the IC. The clock signal was missing on the latches. Replaced the GAL at 65D to fix.

Symptom: Loses most sounds after heating up

Most audio signals disappeared after playing the game for about 10 minutes. Cooling spray had no effect. The audio signals would come & go. Sometimes they would work but most of the time they wouldn't. IRQ lines were going dead when the sounds disappeared. Replaced the 6502A CPU on the sound board to fix.