re-capped fender twin silverface and modded to blackface

[Baxtercat]

I recently fixed a guy's noisy black Fender by simply sliding a rectangular sheet of polyethylene between the two partly conductive boards. Needed re-insulation of the forty years of dirt and rust, esp. near the steel-legged trem bug area.

[Curranproducer]

so slip this plastic stuff between the eyelet and the 2nd card of the board?

[martin manning]

Yes, or you could slip the old insulator card out and replace it with a new one or a piece of G10.

[Curranproducer]

sweeet Love it love it love it!!!

[Curranproducer]

slipped in a new fiber board sheet from doug hoffman, seems to be the crackling is gone!!! NOW it is motorboating when I peg the amp to ten. I did recap the the entire power filter section. soooooooo some input would help for sure! HAHAHA I also got some crackling on the volume pots I replaced as well.

[rp]

Loose connection on one of the filter caps when you moved stuff around?

[martin manning]

Could be that the eyelet board is somewhat conductive (stands to reason) and therefore the problem is only half fixed.

[Curranproducer]

boof, so are you thinking I may have to re-do the entire eyelet board?

[pops]

I have had conductive eyelet boards before and had to replace the entire board. If you measure with your meter from ground to the board near any terminal up to 1/2' away from the terminal and you have more than a very small voltage the board has become conductive from absorbing moisture.

[Curranproducer]

the board is giving me 500mV and climbs up the longer I keep the DMM probes on there. I have moved the probes around to a few different spots on the board and the mV can get up to 1 v. Is this a problem?

[Richie]

I had an older twin reverb here for repair a while back, and made a quick video. It had a very bad conductive board. I was showing different points on the board and the voltage reading.
I just turned the volumes up , nothing plugged in,lightly rub the board and you can hear the static, and how you can find the bad spots, or spots that are worse than others. Some depends on where the problem is, or what section it effects.

Here is the video.

https://www.youtube.com/watch?v=paMScyAQrQw

[tsutt]

I had an older twin reverb here for repair a while back, and made a quick video. It had a very bad conductive board. I was showing different points on the board and the voltage reading.
I just turned the volumes up , nothing plugged in,lightly rub the board and you can hear the static, and how you can find the bad spots, or spots that are worse than others. Some depends on where the problem is, or what section it effects.

Here is the video.

https://www.youtube.com/watch?v=paMScyAQrQw

So what did you do to fix it?

[Richie]

Usually it depends on how bad it is. Sometimes you can lift parts or mount them above or off the board of a problem area.

But the only real fix is to replace the board.

[Stevem]

I have had to do the complete replace the board thing a few times also, but the last time a tried out totally saturating the board with spray flux remover, Had to spray it down twice with it unscrewed and sitting up from the insulator board, but it did the trick and for far less money and time the swapping in a new board!
Just spray it down while sitting in a big plastic bag because as I said you have to use a ocean worth of the spray, and let the stuff evaporate off for 3 full days before you power it back up!

[Richie]

Even the boards that were wax coated still can become conductive. Does the flux bath work on the boards that are wax coated?
The board in the video was one of the worst I had seen or measured.
The whole board was conductive from one end to the other.
Usually it is not as bad as that board, and it may be confined to one section or spot.
But I think once it starts its going to get worse.