Can fuses go bad?


Yesterday I turned on my Halo JC-1s for a little listening. As I walked over to drop a CD in the drawer I smelled a slight burning odor. When I looked back the lights were out on one amp. A check of the line fuse verified it had blown.

Since the Owner's Guide did not specify anything about fuses I sent a message to Parasound to make certain I used the proper replacement (blown fuse was not marked fast or slow blow). In spite of it being late Friday afternoon before a holiday weekend I received an almost immediate reply. Regarding my question on why a fuse would blow a second or two after turn on they suggested it could have become weak. This was a 12 amp fuse, does that seem reasonable?
pryso
Many thanks Dhl. I popped the tops on both amps yesterday. I had replaced the blown fuse with a 10A slo-blo and that amp worked but I didn't leave it on long.

Looking inside it was just as you described. Two of the nickel sized green disk caps had exploded and a third was cracked in the damaged amp. Interestingly, the other amp has only one larger black disk cap (about the size of a quarter), one cap positioned jumpered, and the other two positions blank in place of the four green caps.

My amps are more than five years old. One failed after a year and my dealer sent it in under warranty. I don't have any paperwork from that so I don't even know which amp was repaired. From your comments I suspect it was the one which now has the single large black disk cap.

With your advice I'll contact Parasound tomorrow.
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.
Pryso

Can you please tell me if the JC1 fuses are fast or slow blow?
Thank you.