iMac blowing fuses

MACHEAD

Have a mid 2007 20" iMac, popping fuses as soon as power is switched on. Suspect power supply is cooked, but have been told logic board fault can also cause this. If I could confirm PSU fault I would go ahead and order one up and swap out faulty one. Anyone on here come across this before? As ever any info / tips greatly appriciated.

Sad Professor

Have you ruled out the cable, power socket and the connection in the back of the Mac?

MACHEAD

Only getting back to this now! Yes Sad Professor, am using same power lead and same socket now as I type. (On another iMac of course!!).

Anything relating type of problem I've come across on the web points to a psu issue. On this particular model, the power supply appears to be readily accessible when the display panel is removed.

So hopefully that's the problem, as we can't afford to replace the machine, replacing the logic board would also be ruled out due to cost, and age of the machine.

MACHEAD

Update:

Yes it was the PSU. Have since replaced 2 of them, 3rd on the way! Guess it's the age where those machines are just going to drop out one by one.

ZENER

Most PSUs will suffer from dried out Electrolytic Capacitors which fail with age. Early G5 iMacs were known for it. If they are blowing fuses though, then something more serious has popped.

Did the machines exhibit any start up issues prior to thie fuse blowing ?

Ken