First of all, my apologies for the kilometric title but this seems be the correct one according to MAME which has emulated this game after my dumps 🙂
A friend of mine sent me this Battle Garegga bootleg PCB for a repair :
saying it had bad sound.Infact it was scratchy and noisy:
Besides, sometimes it muted completely.Regarding this last issue, I traced it to a bad YM2151 FM (actually a rebadged version marked ‘PD2001’) sound synthesis chip, once replaced it I got no more mutings.As for noisy sound, connecting the analog output (PIN12) of the YM3012 DAC (a ‘KA3002’ rebadged chip also here) to an external amplifier revealed that sound came out distorted.
Replaced it fixed the sound completely