Amp blowing fuses....

[Big_Bill]

I went to listen to an album today and my Pioneer SA-9500II Integrated Amp blew a fuse at the back of the amp, so I relaced it and it blew another fuse Imediately.....

I unplug the rack every night for fear of something like this, but for some reason last night I didnt. I dont know if it was a power surge or not, nevertheless he we are!

Does anyone have suggestions as to what may be wrong? Does anyone have, or know where I might find the service manual? What course of action should I take next??

Any suggestions will be greatly appreciated!!!!

Thank you all in advance!!!

[jaycee]

If it's experienced a surge then there could be a number of things wrong. Most likely suspect is the output transistors.

Unless you have a lot of experience, this is not a DIY job I'm afraid.

[wintermute]

First thing I would check is for short circuits on the speaker output. Could be the cables, or the speakers themselves. Of course this is not the only thing that could be causing fuses to blow. An inspection of the amps circuit board for any component that looks like it has burnt may also help in tracking down the source of the problem.

Tony.

[Big_Bill]

Originally Posted by jaycee

If it's experienced a surge then there could be a number of things wrong. Most likely suspect is the output transistors.

Unless you have a lot of experience, this is not a DIY job I'm afraid.

Thanks for the quick reply!

I dont know if it was a surge or not. That being said, the power toggle switch was in the off position over night. Can a surge still get to the board if the switch was in the off position?

Bill.

[Big_Bill]

Originally Posted by wintermute

First thing I would check is for short circuits on the speaker output. Could be the cables, or the speakers themselves. Of course this is not the only thing that could be causing fuses to blow. An inspection of the amps circuit board for any component that looks like it has burnt may also help in tracking down the source of the problem.

Tony.

Thanks Tony!

I'll check the speaker outputs first and then pull it from the rack and open her up to look at the boards.

Bill.

[djk]

The thing died from old age.

It will probably need a complete overhaul, including outputs & drivers, probably all the electrolytic capacitors, and misc. other bits.

Like an old car that needs a lot of work, it may be repaired as good as new (if you want to invest the time and money).

Like the old car, it would be a good idea to buy something else to use while doing the repair/restoration.

You may get lucky and have it be simple, but I wouldn't wager on it.

[richie00boy]

If the power switch was off, no surge can damage anything.

[Speedskater]

Originally Posted by richie00boy

If the power switch was off, no surge can damage anything.

Well, a BIG surge can! But you'll have lots of other failures to deal with first. Power amp switches are rather robust compared to many items in your house.

[EchoWars]

Originally Posted by djk

It will probably need a complete overhaul, including outputs & drivers, probably all the electrolytic capacitors, and misc. other bits.
<snip>
You may get lucky and have it be simple, but I wouldn't wager on it.

No argument here, but the 9500II uses a rather strange 'batwing'-style output transistor that is (of course) no longer available. It's gonna require that some sort of new plastic device is somehow shoehorned into place.