Rygar Repair Logs
Symptom: Horrible audio quality
This is a non-JAMMA game and the owner supplied a homebrew JAMMA adapter to use with it.
Fixed a connection on the JAMMA adapter. It was using "Speaker +" and "Audio Ground" for the speaker connections instead of "Speaker +" and "Speaker -". The game's audio came up quite a bit but it was VERY noisy with lots of digital interference in the background.
Recapped the audio section of the board. One of the caps had leaked and the others were in horrible operating and physical shape. Replaced the 2 filter caps on the +5 lines on the top board. One had its solder pad lifted so it wasn't even in the circuit. Swapped out the 220uf @16v filter cap on the +12v line connecting to the final amplifier IC with a 470uf @16v cap.
The game still has some noise in the audio, but this is from the Yamaha ICs in the circuit and is also present on the MAME version of the game. The digital artifiact noise that was in the background is now fixed.