It probably was the fan. Dual ball bearing fans are the way to go. Most switched devices operate fine from 80 - 250 volts. My isolation transformer stops transients like nothing else ever conceived.
Lots of blown up digital controlled chargers around here. I rob transformers and turn them into carbon rod soldering guns.
My BIG charger sounds like a Huey warming up when I throw the switch. It has a transformer the size of a 13" old fashioned tube television set. Rectifiers with TWO OUGHT AWG braided leads. 1.675 KV PIV. I did not screw around when I built that thing. Thirty one pounds of irradiated copper heat sink.
