Rotel ra-940bx tone switch

Hello,
I have a Rotel ra-940bx whose left channel works intermittently. I noticed that the tone switcher might be the cause of the dysfunction as if I play with it the sound sometimes comes back.

Following the suggestion of an amplifier repairman, I tried to spray some wd-40 lubricant and it worked for a while but now the problem is back.


This amplifier is not particularly valuable, but I am kind of fond of it. I would like to try replacing the switcher, to see if it fixes the problem.


I am in no way an expert and I am a bit clueless on where I can find the parts. I searched a bit on the internet but the shops I found did not have the specific part (I would have been surprised otherwise, to be fair).

I would be grateful if you know any shop that might have these type of things or if you could point me in the right direction for a more successful search.
Thank you


Duccio
 
WD-40 is low-odor kerosene. It does OK for short-term sealing of cracked spark wires. It is a short-term lubricant. It evaporates in days/weeks, so you have to do it again. Each time it collects dirt and works it further into a joint or keyhole. The only real use seems to be to soften some types of tape-glue.

There are MUCH better cleaners or lubricants. CAIG is well-regarded in audio circles. Yes it seems expensive but a teeny droplet is a long-term fix for many intermittents.