Riveted PCB - Peavey Ultra Plus

sahlomonic

sahlomonic

Well-known member
Picked up an Ultra Plus for an absurd prce of FREE yesterday :p, but it does not have sound (was forwarned prior to receiving it). Upon brief inspection inside the amp, looks like a power tube arced on the socket. I can remove the impedance and pre-out boards, but the power tube board looks riveted to the sockets on the chassis, as I think was standard for a lot of Peavey amps. What are some ways I can tackle this without destroying it?



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I’d call peavy to see if you can get another board assuming it’s too far gone. I’d think they used that board across multiple models. Then if you can get an extra I’d drill out the old rivets and swap it out. My method for that is to create a bowl with tape sticky side up so the metal shavings stick to the tape and stay out of the chassis.
 
Aynirar27 said:
Rivets suck man. It may not be the best option, but you could certainly drill them out and just replace them with threaded standoffs.
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That was my original thought. I think dealing with the rivets will be the most frustrating part. I hope it's not bad enough that the board needs to be replaced, but won't be able to tell until I can get the board out and the carbon cleaned off, then do some continuity testing.
 
ZEEGLER said:
Any update on this yet? Did you get er running?
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I haven't had much time to get into it, but I drilled out the PCB tonight. I think I can jumper the blown traces on the board, and may need to replace a diode that appears to have scorch marks surrounding it on the board, but the diode itself doesn't show any burn marks.

Before I took the board out, I powered up the amp using a Variac starting at 0 volts, and shortly after the heaters turned on it cooked a resistor on the main board coming off the half power switch. Not sure what that relates to.

For now, I'm going to focus on replacing the blown/questionable components that I happen to have on hand and jumper blown traces. If that can at least get it running, then I'll look into replacing the power tube board just for insurance.
 
Note the traces in the first pic. Is this delamination? Oxidation? Is this caused by excess heat/voltage/short?
 
Well good luck. That board looks crusty! Hope you get her working.

I'm picking up another Ultra Plus myself this Sunday. I don't know why I need another one, but I'm trading a couple of things I don't use for it, and it supposedly has just been serviced and is in 100% working condition.
 
Emailed Peavey about a replacement board. Guy that emailed me back says it's no longer available, so it looks like I'll have to try and rebuild it. I replaced two 100r resistors that were torched, and there's an SR2783 diode that looks torched too. Diode test on my multimeter showed 14M resistance one way. Can't seem to find those via Google search. Haven't tested the SGRs but I remember those being a weak point on a lot of Peavey amps.
 
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