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Hey y’all, this TSL100 came in— 8ohm and 4ohm outs are not working. I pulled out the HT fuse which was fried and replaced it. I pulled out the output board and it’s pretty gnarly under there (it looks like oxidization and burns from and I notice CON1 on the motherboard is fried, which would explain burn marks on output board. My question is if anyone knows what the underlying problem could be. I believe CON1 goes to bias so it might have the infamous bias problem, there may be burnt traces on the output board but I’m not sure. Anyone have any suggestions for good circuit board cleaner? I’m diving into amp repair and I haven’t worked on tsl100’s before. Any info helps! Thank you 😎
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Not sure how to upload pics yet but I’ll get pics up here shortly -
This amp has the ground side of the 4 and 8 ohm taps switched off the 16 ohm socket. If the 16 ohm socket contacts get oxidised it can cause problems with the other 2 sockets. I use isopropyl alcohol to clean sooty crud off boards, sometimes acetone if needed. I always wire the grounds of the output sockets together, and this guards against future problems. The original idea was to prevent the 16 ohm socket being used at the same time as the others, but the problems this arrangement eventually cause are far worse - arcing, tube failure, OT or PCB failure are all possibilities.
CON1 being burnt suggests excessive voltage. Could be a result of the output board problem, but I would try to establish which pins or board area are most burnt and compare this to the schematic. I've had plenty of bias issues with these amps, but bias creep alone won't case the connector to burn. Check to make sure the output tube sockets haven't arced as a result of output socket problems.
It's always a good idea anyhow to check the bias board any time you work on these amps.Comment
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