Repair of a broken slide balance pot

[MattiaM]

Hi,

I am repairing a vintage amplifier which has many issues, including a broken slide potentiometer with center detent for balance control.

One side of the control works just fine, whereas the other has a broken connection between the resistive element and the pin from which current should flow. it's a microscopic fracture in the flat conductive trace barely noticeable, but it's enough to break the connection.

Since the part is unobtanium, I was thinking of ways to fix it. I can't put solder on it because it needs to stay flat in order for the wipers to make good contact and to not get stuck.

The only options I have in mind are to cover the fracture with conductive paint, or with some conductive epoxy.
However, I am worried about the wipers might just take it off after a few strokes.

Does anyone here have any advice or suggestion?

Thanks

 

[MattiaM]

After some cleaning, the fracture in the broken trace is now quite large.
Here is a video with the broken pot:

YouTube

 

[gflash]

You might use electrically conductive glue/ink. I don't think that the resistive element is solderable.

 

[MAAC0]

On my amplifiers the balance knob stays always in the same place (middle). Why don't You just replace it with two resistors ? Leave the original just for cosmetics. You can always put a rotary pot in the back side case You ever need it.