I got this Street Fighter II – The World Warrior PCB from my friend Joachim for a repair :
Gameplay was fine (strange thing since CPS1 hardware is higly unreliable) but sound samples were missing or played randomly :
Samples are played by an OKI MSM6295 chip located on A-BOARD which take data from a ROM on the B-BOARD, looking at it I noticed some sign of reworking with a jumper wire too:
Continuity of traces was good so I opted for replacing the chip :
This restored the sound samples, end of job.