On 9/22/2012 4:52 PM, supervinx wrote:
Well, I made some more measurements.
The IRFPE40 shows the following voltages:
VDS=312V (max. 800V)
VGS=0 (?????)

What's the IRFPE40 function ?
Looking at the PCB it seems that the 3844 supply voltage comes from it...

Are you looking at this with a scope?
I've seen many instances, especially in monitors
where a cap has gone high resistance. You measure the average
volts with a voltmeter, cause that's what's being regulated.
But look at it with a scope and you see high peak voltages
that make stuff HOT...just before it explodes.

Probing around in the line side of a switcher with a scope
is a good way to make a dead psu and a dead scope and a dead
technician. I use fully isolated probes.