Submerged Bassman

[sonicmojo]

This is a new repair request for me, a '65 Bassman that was supposedly underwater for 30 minutes, not sure if the water was salty or not but it was near the beach in a house during a massive rainstorm here in Hawaii last year. This happened about 8 months ago and it seems to be fully dry now but a bit rusty inside. I doesn't have any old paper caps and I can't think of any water that would still be trapped anywhere except maybe inside the transformers. After cleaning pots, sockets, jacks, and switches, it fired up on a light bulb limiter okay. I'll be cleaning it up some more but I think it survived.

bassmanunderwater.jpg

[martin manning]

Rainwater, I'd guess. Salt would be a disaster. It'll likely give up more moisture as it's used, with the heat and all.

[ER]

I knew a guy who was a real tone head that had a 2x12 fender cabinet that was in a flood, he called the speakers "silt-tone", it sounded amazing.

[pompeiisneaks]

Very interesting, you may want to put the thing in an over at like 100 or 125 for a few hours just to ensure it gets any remaining moisture out (unless it's been out of the water for a long time).

Would love to hear how it turns out.

~Phil

[Reeltarded]

It's like a fossil you can play!

Uncle Salty

I wonder if the water caused all those lead dress issues?

[sonicmojo]

Yes, should have put this in the technical section as it is a wild goose chase now

It is very hissy.

If I ground the grid at V2 or pull that tube, all the hiss goes away but I'm having some issues finding the source. Replaced some resistors in the area where I thought the problem was occurring but to no avail. There is also some voltage on the board as these boards are typical to have. Will keep searching....

[Phil_S]

Hiss = plate load resistor?
Voltage on the board? It's only going to get worse. Regrettably, it's going to need a transplant at some point. You might as well get it over with.

[pompeiisneaks]

Hiss = plate load resistor?
Voltage on the board? It's only going to get worse. Regrettably, it's going to need a transplant at some point. You might as well get it over with.

agreed those tend to go bad, and being wet may expedite the problem.

~Phil

[sonicmojo]

Yes, it was a plate resistor on V1! I could have sworn I probed the noise just after V2's plate but replacing the 100Ks on V1 did it. It is quiet now but I'll keep it running for a while and see what else pops up.

Thanks!

[sonicmojo]

I'm getting weird readings trying to bias now, lot of jumping around that changes on tapping of the tubes or even changing the volume control, or just breathing on the amp..... Time to really scrub and tension the sockets, perhaps check all the groundings. This one is getting fun.

[Stevem]

Use a cut off length of a round wound string wet with some 70% rubbing Alky to scrub the tube pin sockets .

[Reeltarded]

I'm getting weird readings trying to bias now, lot of jumping around that changes on tapping of the tubes or even changing the volume control, or just breathing on the amp..... Time to really scrub and tension the sockets, perhaps check all the groundings. This one is getting fun.

You idea of fun always freaks me out just a little.

[sonicmojo]

You idea of fun always freaks me out just a little.

Yeah, I'm nutty this way. Cleaning the sockets cleared up the bias fluctuations. Now onto a minor hum and more rust removal if the customer wants to pay for the time...maybe I should just spray it with OSPHO, works on my '85 Landcruiser.....and I've discovered that old amps are really just the same as old cars. If you don't drive them, they go bad. And try not to drive them into a lake.

[Reeltarded]

Yep. Porsches for 35 years. Turns out that I live in a very wide rust belt.

[Colossal]

Hmm, maybe that should be an Electric Hawaiian instead of a Bassman!