Quote from: pickdropper on December 10, 2020, 03:07:23 AM
Sorry, I haven't been on the board much lately. If your board is toast, I am sure one of us has another one we can send you.
To answer your first question: I don't really see how the biasing could cause the circuit to stop functioning unless the trim pots themselves failed. If you hadn't taken it apart, I would've suggested audio probing to see exactly where the signal stops. Also, the board looks pretty clean. If you washed it, did you do that before or after the trim pots were added?
Hey! No problem at all. Thanks for chiming in. I swear I build enough that I can usually troubleshoot any issues on my own, but I was just stumped by this being the second TB side of this board that I couldn't get going, even though the FF sides always worked first time .
The trimpots were pretty much the only thing I didn't try replacing, as they seemed to be functioning fine. In the end, I fluxed and reflowed all joints, replaced transistors a few times (including different types), removed all components with a hot air station and re-populated the entire thing and probed/measured in between each stage, with varying results.
I have to assume it was poor SMD soldering on my part that kicked this off and call it a day (though the FF side looked no better and worked fine).