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About Mosfet

Hi Audiogonians, Merry Christmas.

I got some questions about MOSFET.

First I would like to know how can one damages a MOSFET? Can wrong connection from powersupply kill it? Next up is how does a damaged MOSFET sounds like and how can one knows which one is dead if there are more than one in a poweramp? Finally, if there such a thing as life span of a MOSFET?

Equipment-Adcom GFA5500. Problem-One channel sounds like a weak reception radio. Cause-could be wrong connection. Can someone help me to trobleshoot this?
rainchild
bombaywalla's avatar
bombaywalla
1,958 posts
 
Unsound,

I feel that it cannot be the fuses. If the fuse is blown, then there'll be zero (or no) output. Rainchild reports "Problem-One channel sounds like a weak reception radio".
IMHO.
unsound
7,335 posts
 
Bombaywalla, recently I blew a fuse on one channel of a stereo amp. The channel with the blown fuse continued to play music, albeit scratchy and distorted. After reversing speakers and cables, changed sources and eliminating the pre from the system, no luck. Then I checked the fuses. One new fuse, no problems.
unsound
7,335 posts
 
P.S. it was an all Mosfet amp.
rainchild OP
31 posts
 
Thanks guys,

Oohlala, Bombaywalla knows so much, how I wish I could be like you. I'd checked and yes, I got a 8A blown fuse. I'll replace it tomorrow and see how it goes. Thanks Unsound. Like an AM radio with bad reception. Is that what you've experienced?
bombaywalla's avatar
bombaywalla
1,958 posts
 
Unsound,

Incredible indeed!
I didn't think that a blown fuse would allow any power to that channel. Must be the way that the fuse was routed into the circuit. Many times amps have fuses but they are not in the direct signal path to avoid spoiling the sonics. In such cases the fuses do their job but not like a traditional fuse which might be in series with the circuit path & once blown would create an open circuit.

Ok, Rainchild, check them fuses!
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