Re: Really universal soldering controller Reply #3600 – November 23, 2020, 07:42:45 pm Quote from: afedorov on November 22, 2020, 02:21:27 pmI mean he put a very little effort in debugging still and this should be an easy power thing. And you advised to spend $100 on top of already spent $80 or so and throw those $100 in the bin.I would follow the power path, starting from AC voltage after the fuse. May be measure voltage drop around R9, check R47, R51 divider resistance. The problem with incorrect zeners was already discussed and solved here.Thx for support. I did not see much of a benefit of moving parts to a new PCB either as the fault is within some components. I personally prefer to document this kind of issues and troubleshooting in this thread as this can help other people in the future. I done some more diagnostics but I stopped getting correct voltage on J3 and zener diodes voltage on ZD2 ZD1 is to low. I suspect faulty Q1 FZT605. I will give some more update once replaced. Once again thank you for support.