Yamaha M2 Input level Pots / Volume knobs

[Jazzmuso]

Hi everyone - best wishes for 2024
I am having a problem with the right input level control on my M2 amplifier. It turns with difficulty and induces a hum for a few minutes when I switch on from cold. Not sure there is an equivalent replacement part of whether it can be sorted with Deoxit or similar treatment.
I am pairing it with a C4 preamplifier. Its part of a full Yamaha system with NS 1000 speakers and PX3 turntable.
Any advice or leads will be appreciated.
Regards

 

[avionic]

Not sure there is an equivalent replacement part of whether it can be sorted with Deoxit or similar treatment.

I'd try to remove ,disassemble and clean first.

 

[Alonia]

I'd try to remove ,disassemble and clean first.

However, the procedure should be used with caution!
You can break more than you fix if you've never done it before.

More than 90% of the time it is due to the sliding contact. This tarnishes over time or a kind of oxide layer forms
(depending on the material and how it was treated (galvanized / ...)).
The approach of simply spraying in a bit of contact spray is crap. It only works for a short time and later it's even worse than before.

Here are a few pictures as an example:




The potentiometer usually has to be drilled out because the shaft at the end of the potentiometer has been deformed. To reassemble it later, the shaft must be drilled and you need to make a thread cut. Here you are moving in a range of perhaps ~1mm so the risk that you break the drill is very high!
Cheers
Alonia

 

[Jazzmuso]

Thanks for responses. I am not handy at all so will not attempt any home repairs. Will chat to a tech I trust over the weekend.