Can fuses go bad?

I would also check those surge current limiters, esp if you have an older production JC1.

They are on the AC input board and look like large green capacitors. The older design has four of them clustered together. These can "current hog" and burn out with sparks and smoke. The newer design replaces four of them with two much higher rated ones.

On one of my JC1s I was seeing arcing in the vicinity of this board when turning on my amp. It was sometimes accompanied by a burning smell and smoke. When I took the board out and looked, one of the surge current limiters was literally blown out in the middle with chunks of encapsulant missing. I am lucky they did not catch fire.

These limit the surge current going the power supply capacitors and come under a lot of stress on start up. The parts in the older design were underrated for the large amount of capacitance in the JC1 power supply.

Tony in the CS/Tech Support group at Parasound will send you free replacements or you can send the amp to them for replacement. If you have the older ones, get these replaced ASAP.

Pryso:

Looks like one of your amps has the replacement. The new parts are larger and thicker (and black in color). The originals were arranged by two parallel pairs in series. They are all replaced by one single part (although I used two of the large parts in series in mine), so the traces for one pair are shorted.

If you have cracked or damaged ones, DO NOT POWER UP your amp and send it to Parasound immediately (or fix it yourself). Those damaged current limiters can catch fire and you do not want that.

I think Parasound should have recalled all the older amps. This is a dangerous safety issue that should not be left up to customers to discover on their own.