HP97: Who was the killer (resistor or transistor)?

[Geoff Quickfall]

That's not mechanical (kinetic) damage. Looks more like a over current fracture damage. Reminds me of my grundig 4035 restoration. Two obvious damaged resistors in series on the same circuit. Tracing from the power supply to the resistors resulted in an higher current through the circuit then designed causing both resistors to fracture then fail.

Highly doubt that it was a physical impact as the board would have also shown indication no of trauma.

Grundig restored:


Before:



After: