Hello,
I have a computer switchmode supply that I'm trying to repair.
The problem is that it runs for about 10 seconds while putting out a strong hissing sound, and then it stops. I think the sound might be coming from the output inductor.
I've checked bad solder connection, bad caps, the secondary side rectifiers, all good.
From what I've seen, it seems to be a half bridge converter with the controller on the secondary side.