I didn't solder the big SOT223 tabs. Is it recommended to do that? Thought of easier removal in case of a problem. I agree that there might be a bit too much solder on the other SOT223 pins, but being small they are difficult to solder. Considering the general amount of solder used on the other joints, I was aiming to achieve "ok" joints as seen here:
The iron is around 370c or 430c. Don't remember exacty. What is recommended?
@Kevin For the HV lines, I use silverplated wire with teflon, they tin very easily and I doubt that this was the problem. When I removed the wires from the terminal blocks I did not have the impression of not tightened screws. But it's hard to exclude of course.
so that actually looks like an overheated pin due to poorly tinned wires (or no tinning) or not screwing down the wire tight enough.
Seen this on too much expensive lab equipment. So the pin overheated, then all sorts of bad. The trace it was shorting to is the feedback line and is close to 0 volts
Did you solder the big collector tabs on all the SOT223 package transistors for better heat transfer? I would wick off some of that excess solder clump on the smaller tabs, too. It looks like you use general amounts of solder in general, less would help (including on the terminal blocks). What temperature did you set your iron to?