Recent repairs for a friend. 7 separate devices (6 tool battery chargers -5 Ryobi units and one Skil charger) and an oven controller were brought to me after having failed due to an extreme overvoltage condition in an off-grid cabin.
All of the chargers are fixed now, after a significant number of fairly straightforward component replacements.
In this case, the “defensive”, sacrificial components in the circuit designs -mainly varistors, current fuses, and solid state thermal fuses – sort of did what they were designed to do and blew into open or shorted failure as designed, but not quickly enough to save a significant set of early stage power supply components. There were some spectacularly blown electrolytic capacitors and varistors, a fried transformer, and some failed switching ICs, but everything past the power supply stages of the circuits turned out to be OK.
I have a vp215 that isn’t completely getting all the air out of the bag now. I spoke to AVY…