[Amps] Flashover and QSK board in TT Centurion

[Ignacy Misztal]

A few minutes after being turned on, my TT Centurion made a loud bang
and went dead. The trace on the HV board from the transformer to
diodes evaporated. There was not any damage visible anywhere else.

I patched and the amp amplifies but it is always on, and additionally,
the red LED in the power meter is always on. After checking, all CMOS
(4011 and 4093) inputs and output are 14V.

This is the third problem with the QSK board. It seemed to occur to
the previous owner and it occured to me before after replacing a fan,
although there was not any flashover or band and just one gate wrong.

I ordered the ICs + sockets to avoid (un)soldering. But there are two questions.

1. Why that trace burned? There should not be high currents between
the transformer and the rectifiers. If there was any probelm with the
rectifiers/capacitors, perhaps something else would have fried as
well.

2. Are CMOS chips too fragile to be put 1 inch directly above the PS board?

73,
Ignacy