Denon PMA-520 right channel not working

[tomferno]

Hello,
I have an old Denon PMA-520 amp and I have never had such a good sounding amp.
Recently I had an issue when I select the Source selector in "Normal" or "Subsonic" mode, there is no sound on the right channel (or very quiet). But when I use CD-Direct everything works fine.
I tried to invert the speakers and it's the same thing, so the speakers are fine.
I cleaned the whole amp with contact cleaner on the inside. The issue was solved for about 1 or 2 days and it came back
Does anyone have an idea from where this issue can come from ?
It would be a mess to throw this amp away as it's such a sweet sounding amp !
Thanks
Tom

 

[painttoad]

deoxit d5 on the source selector,tape monitor and the buttons. work 100-200 times

deoxit f5 on potentiometers. work each 100-200 times.

contact cleaner dries too fast to really clean anything cruddy or for very long, as you saw.

 

[tomferno]

deoxit d5 on the source selector,tape monitor and the buttons. work 100-200 times

deoxit f5 on potentiometers. work each 100-200 times.

contact cleaner dries too fast to really clean anything cruddy or for very long, as you saw.

so you think it's just a switch contact problem or a balance poti problem ? Nothing with an old solder issue ?

 

[painttoad]

so you think it's just a switch contact problem or a balance poti problem ? Nothing with an old solder issue ?

it could be a solder joint on that switch.

now i see that you only cleaned the inside of the amp with contact cleaner, you need to get the chemical in the switches.

 

[tomferno]

will try this out. I found the Deoxit products on a german site.
Thanks for your help. I'll keep the thread updated

 

[painttoad]

i just took a look at some pics of the inside, that switch is cable driven. get some contact cleaner inside the switch itself and work it a couple dozen times and see how it goes.

it's white in the pic i saw, back by the inputs