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
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.