Peavey Ultra Plus 120 head shooting lightning!

[Danglin' Fury]

So I have this amp on my bench...had it for a while... I'm pretty sure the dude spilled beer or something in it.. So I power it on, just to warm up the tubes... They light up and I hear static from the speakers... Then zap! Lightning shoots across the heater path on the power board... It is arcing over traces and severely damaging the board... It came in like that and I had to dremel out the carbon and I took out that shit ribbon cable and put 16 gauge wires where they used to be... All was well and then poof... I changed a couple of resistors that smoked... The 5 watt resistors are all ok... Diodes are ok... It does this even when I pull the power tubes... I measured across the fillament voltages and I'm getting like 22-24 V AC... Any ideas? Thanks guys....

[xtian]

You should post photos for us (especially of the moment the lightning happened!)--though my gut tells me this is a lost cause--conductive board, multible flameouts, Dremel on PCB action...

[Danglin' Fury]

I think you are correct... I've repaired a lot of amps... A gaggle of Peaveys.... Lol! Never had a pain in the ass like this... I'm trying to upload a pic... It keeps telling me the files exceed the size allowed... Wtf?

[The Dude]

You should post photos for us (especially of the moment the lightning happened!)--though my gut tells me this is a lost cause--conductive board, multible flameouts, Dremel on PCB action...

I agree. Some photos would help. This is obviously not a standard repair.

[Danglin' Fury]

Yeah... This thing is a biiiiiiitch! Lol! As soon as I figure out how to shrink the damn size of the pic... It says it allows a 3.00 k pic... Mine is 3.13 k.... Daaaaaaaaaammmmmmmiiiiiit!!!!
Lol!

[DrGonz78]

I run photoshop on windows and that is the type of software you want to change sizing of an image file. However, I really like Gimp on my Linux system. You can go to this page here and download Gimp for Windows, just scroll down.

https://www.gimp.org/downloads/

Edit: Never ran Gimp on Windows but I bet you it works fine. Only trouble people might run into is Javascript stuff.

[The Dude]

FYI: You can get a full legal copy of Photoshop CS2 free. It only requires registration. Here's a link with instructions.

Download Adobe Photoshop CS2 For Free Legally While You Still Can [Tutorial] | Redmond Pie

[Danglin' Fury]

Got it... Operator error.... Lol!

[Danglin' Fury]

When I first got it, somebody else had been in it... I cleaned it up a lot...It was working fine after I got it running..then it shot the white light and hasn't worked since..

[Danglin' Fury]

Anybody?

[nosaj]

I run photoshop on windows and that is the type of software you want to change sizing of an image file. However, I really like Gimp on my Linux system. You can go to this page here and download Gimp for Windows, just scroll down.

https://www.gimp.org/downloads/

Edit: Never ran Gimp on Windows but I bet you it works fine. Only trouble people might run into is Javascript stuff.

I use Irfanview small footprint many plugins resizes files easily.
Nosaj

[nosaj]

Ultra 120a.pdf

Anybody?

I realize it's a long shot. You pulled the output tubes. It looks like the preamps are on the same filament run have you pulled those?
What about divide and conquer it looks like there are connectors linking the boards maybe just the output PCB is just shot or possibly something else causing excess filament draw. What about the tube sockets carbon traces?
Didn't notice a schematic so here's one for everybody up there at the top of msg
nosaj

[tedmich]

Maybe make a movie in a darkened room and post it to Youtube!

Carbon traces on a burned board can be very hard to remove and HV will find them if you don't get every bit and then maybe coat with 2 part epoxy.

I re etched a board to fix this


Matt Weed at Atomium Amps (PA) posted this:
"Warning: graphic imagery. Gutted 5150II. Still trying to figure out what to do with this one, since the power tube PCB is burned through in multiple places and completely shot, and there are component failures all over the amp. Basically, one initial flashover carbonized enough PCB area to permanently couple the plate voltage into the heater circuit, which blew every single tube in the amp, preamp cathode circuits, the LV relay supply, heater reference resistors, and a few sundry other bits.

I suppose the moral of the story is that you should always take an amp that “makes lightning” to a tech immediately. Don’t assume that because it turns on again that it’s ok, and don’t sell it to an unsuspecting buyer without telling them."
see:http://atomiumamps.tumblr.com/page/33

I think he tossed the boards