A friend has asked me to take a look at his guitar amp: Peavey Valve King VK212.
Problem: suddenly the amp stopped working during operation and the status lamp went off.
First reaction: fuse replacement, the status light came back but zero sound.
This is my starting point and observations (full schematics are easy to google, I have doubts if it would be fine for me to share, though):
- Fuse F201 clearly burnt, but continuity tester shows flow on both sides! Obviously short circuit is somewhere around. Resistance measured on bot ends of the fuse = 14 ohms. This confirms the fuse is dead and flow is another way.
- Capacitor C201 looks slightly damaged, I bet it is short circuited and blew the fuse.
Now two questions to experienced colleagues:
Q1: I localized at least these two faults. How far do you dig to avoid cooking the parts directly after replacement? I mean is there a rule of thumb to say "ok, I got to the root cause, can do the replacements and switch the thing back on". Ideally I should probably check the whole module but it means soldering quite a few parts out of the circuit to measure them... But maybe at least the diode bridge that follows right after?
Q2: Basically all plugs on the plate are additionally glued. Is this because of the guarantee, or is this to make sure they hold despite vibrations of the amp? Basically I would like to know if I should glue them again after the repair.
Thanks in advance for any hints!