Received some days ago a box of faulty boards for repair.There was a clean Sunset Riders PCB:
Game played fine except for sound since samples were only noise (music was fine instead):
Sound samples are stored in a 8Mbit MASK ROM @1D:
MASK ROMs check reported it as bad:
I was sure device was really bad (Konami ones are well known to be prone to failure) so I removed it :
But it turned out to be good instead since reading it ended up in a good dump and also replacing it with a programmed 27C800 EPROM had no effect .
Sound samples circuit is very simple, the ASIC ‘053260’ (a custom PCM/ADPCM sound chip) addresses the MASK ROM @1D and plays its data:
No other component is direclty involved so most likely the ASIC was the culprit.I removed it :
Took the spare one from a scrap Asterix and soldered it back on my board:
Success!MASK ROMs check reported now a good device @1D hence board 100% working and fixed :
2 Responses to “Sunset Riders repair log #6”
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Nice work Caius, it’s funny I fixed a Lightning Fighters with the same issue (no sound / bad maskrom) the day you posted this. Mine turned out to be a bad YM2151 rather than the custom though. 🙂
Thanks.Konami customs are pretty reliable including this PCM player, it’s the first time I replaced it all my repairs.