Hi All, I bought an SQ-80 from the USA (I’m in Australia) which has just arrived. It was listed as having issues, looked like it was just a battery replacement from the photos in the advert. On arrival it wouldn’t power up at all. I noticed some green goo in the provided IEC power cable and in the IEC female socket. I replaced all of the fuses, the AC filter and did a check over of everything. Also changed the battery. The unit now powers up reliably but I’m not getting any audio output. Reading the service manual it seems like the CEM3379 and the TL084 are the most likely problem. Getting the CEM3379 isn’t going to be easy or cheap. Any thoughts on other potential reasons for no sound before I go ahead and try to source the CEM?
What little documentation I’ve been able to find tells me that there is one CEM3379 for each of the eight voices. No sound would imply that all of them are out, or else the circuit following.
Have you put a scope on the output lines?
Check pins 6 and 9 of U44 if it gets any signals. If this is not the case replace U39, otherwise replace U44.