Peavey Triumph Switching issue - Help please

[LooseChange]

See the attached schematic.
The fuse blows only when the footswitch is connected.
Trial and error could blow lots of fuses.
What might be the problem??

Thank you!

>>>>I updated the schematic and attached to a reply below.

[jjasilli]

Somehow I'm not finding the footsw on the portion of the schematic posted.  But, meanwhile, maybe use a circuit breaker, instead of a fuse, until the problem is resolved.

[LooseChange]

The foot switch circuit is the circuit just the the lower right of the bridge rectifier. It says "6 PIN DIN" at the top of the connector.  Don't have a circuit breaker device. Thanks!

[Geezer]

  Don't have a circuit breaker device.

Do you have a light bulb current limiter?

[LooseChange]

Do you have a light bulb current limiter?

Yes. Do you think that will work and actually give me some visual feedback?  The fuse just protects one small part (27v) of the circuit.

[Geezer]

Oh, sorry.....thought it was blowning the mains.......no, that won't help.

[LooseChange]

Here is the schematic with the Foot Switch circuit in the red box.

[DummyLoad]

lamp limiter will likely still pop fuse - ckt is limited to <30 watts.

with S7 norm/bypass open or closed? if either way there is likely a short in the cable.

look for a short between pin 3 and the shield pin 5 otherwise i'd suspect C33-37  or CR3-5, but that just doesn't seem possible - there are 470 ohm Rs in series with each relay ckt. so the most current that would flow if there were a short behind R54,55, or 56 would be 27V/470R or ~60ma hardly seem enough to blow a 1A fuse. look for cable/connector problem.  

[rzenc]

Does it work - switches - without the footswitch? I mean switching thru pannel switches?
Maybe C48 went south?

[plexi50]

I didnt see this thread until now. Let me go look at that schematic. I have worked on a lot of those peavey amps. I made this circuit breaker 5 years ago or so. Fuses are too expensive to go through them until you find a problem

[Willabe]

I made this circuit breaker 5 years ago or so. Fuses are too expensive to go through them until you find a problem

plexi, whats the part #/ spec's on it?


            Thanks,     Brad     

[plexi50]

The parts in my red square are all i can see in the circuit that could cause that fuse to pop. I have heard a pop when switching using the footswitch before and changing those caps was the cure for me

[plexi50]

I made this circuit breaker 5 years ago or so. Fuses are too expensive to go through them until you find a problem

plexi, whats the part #/ spec's on it?


            Thanks,     Brad      

There is no part number on this one. I got it at my local parts house here 4 years before they closed up
There was a box of about 50 of them. I knew then i should have bought at least 3 of them but i was in a hurry as usual
It was one of those 75 year old electronics part houses that had everything from tubes, testers to scopes and speakers,cloth wiring you name it

What a bummer it is that they closed up. You can get a small breaker like this a from Newark or Mouser im sure