On Fri, 18 Sep 2009 13:27:48 +0100, Fred Bloggs wrote:
There's no primary-side switching transistor, which is unusual.

I thought that, too. It is off-board somewhere, or soldered onto the
reverse side of the PCB (which would also be unusual)?

But yes, that or rectifier diodes. I'm not sure if that's some kind of
thermistor near the fuse; if so it *might* have gone bad, although that's
less likely.

Worth checking the main smoothing capacitor, too; whilst it may not have
shorted, it may have gone bad and be the cause of failure in whatever
component *has* made the fuse blow.

It could be a fault on the LV side, too - but checking the obvious on the
HV side should be quick and easy and is more likely I think.

your picture isn't clear enough for me to read the
markings on IC1 to look up the spec.

Looked like a prefix of V1F / VIF / VTF / VLF and then -22A to me,
but none of those cough up anything via Google unfortunately. Seems
unusual that an IC would no heatsink could do the job of switching,
though. Unless the heatsink fell off, which is why it's cooked :-)

cheers

Jules