On Dec 4, 8:34*am, Wond wrote:
On Sat, 03 Dec 2011 13:17:22 +0000, N_Cook wrote:

Not really detective work. My repair methodology starts (after initial
powered up assessment if appropriate, then dismantling) *with a full
viewing under a x5 illuminated inspection lamp+ bulbous lens. Noting
unusual device types, large R values if no schematic, state of solder
joints, insulation, discoloured areas etc. I just saw what initially
looked like a non-cropped off wiring-end ,through the valve base tag,
ending too close to a pin 1 to pin 7, bare cross-coupling wire. Up to
then I was thinking mains transformer interwinding fault.

Physical inspection is an important part of the diagnostic process. Good
eye.

In my youth I impressed the hell out of one of my dad's friends, just
because I spotted a break in a pcb trace in his broken transistor
radio. ("Let spam take a look at it. He knows all about electronics.")
A second with the soldering iron set it right.