Amplifier (JVC-SA22) : blows external fuse. Transformer Problem ?

[Jim Nomad]

Initially after the amp stopped working, I checked the external fuse, which was fine. Then after opening her up I found the two slow blow internal fuses had gone. These I replaced, and now the external fuse keeps blowing whenever I switch the power on. Could both problems be symptomatic of a faulty transformer, and how could I trouble shoot the problem. I love this amp !!

Thank you ....

[HayZee518]

you're lucky to have your amp protected internally with fuses. most don't use any.
check the circuit diagram for fuses in the power supply. if yours is a half wave with a center tap, then one of the diodes are shorted. it may also have a bridge rectifier connected across the two outer leads of the transformer which will give you full rectification of the sine wave.

[valveradio]

are you sure you have fitted the correct current fuses internally? if you have used higher amperage fuses than before then the external fuse would fail first i would suspect. the problem sounds like a blown output stage, possibly being caused by faulty speaker wiring or even too low impedance speakers being used. i would be very suprised if the mains transformer was at fault.

regards, peter