Why audio amplifier is blowing fuse?
I have an audio amplifier (FPL 400) which constantly blow its fuse when started. I reproduce it even without speaker connected or audio input source.
The fuse is located just after the power supply cable.
I did tests by isolating some parts. When I disconnect the cable A and B, the fuse blow but when I disconnect the cable C, it didn't blow (see photo). So the cause must be in the main card.
No component of this card seems visually to be degraded, so I don't know which one is defective.
With a multimeter, how can I identify the defective component?
I did my tests with slow fuses, same as provided by the manufacturer (T1AL250V). I also tested the diode bridge after having unsoldered it and it was ok.
2 of the transistors looks to be ok (between 0.5 to 0.6 with the diode test). The 2 others ones are both at 0.0v.