Yamaha Silverface selector switches

[MonkeyRelish]

I see lots of threads where one channel is missing, or sound dropping out.
The usual recommendation is to clean the selector or coupling switches.
These are all slide switches, and are hard to get De-oxit inside.
Even if you can get some inside, there is no guarantee it will work.
I purchased a CA-600 cheap which was listed as working fine through the tape input,
but nothing through the Aux or Phono inputs.
I was pretty that the problem was the function switch.
The photo’s below show what is required to clean these contacts.


In this case, the tarnished contacts weren’t the whole issue, the plastic cog was mashed underneath.
Flipping the cog over, a bit of creative modding to make it work, and works like a bought one.

 

[clinic-audio]

Hello

What is the part number on it ?

KA50021.....?

 

[avionic]

Hopefully you cleaned all that oily deox-it over spray off the board before you reinstalled.

 

[MonkeyRelish]

Hopefully you cleaned all that oily deox-it over spray off the board before you reinstalled.

Yes I did. The previous owner’s “tech” had tried the De-oxit fix to no avail.
Looks like he gave it a bath.
I only used a bit of De-oxit on the cleaned contacts to help stop future tarnishing.

Mr Relish

 

[MonkeyRelish]

Hello

What is the part number on it ?

KA50021.....?

KA50027 45 going by my photos, but I can’t tell if there is a number between the 27 and 45.
Doesn’t look like it. The board is reinstalled, and the amp buttoned up.

I’ll check when I replace all the electrolytics. Waiting on Digikey ATM.

Mr Relish

 

[rottalpha]

I see lots of threads where one channel is missing, or sound dropping out.
The usual recommendation is to clean the selector or coupling switches.
These are all slide switches, and are hard to get De-oxit inside.
Even if you can get some inside, there is no guarantee it will work.
I purchased a CA-600 cheap which was listed as working fine through the tape input,
but nothing through the Aux or Phono inputs.
I was pretty that the problem was the function switch.
The photo’s below show what is required to clean these contacts.

View attachment 1960310View attachment 1960311View attachment 1960312View attachment 1960313View attachment 1960314View attachment 1960315View attachment 1960316
In this case, the tarnished contacts weren’t the whole issue, the plastic cog was mashed underneath.
Flipping the cog over, a bit of creative modding to make it work, and works like a bought one.

Did you also cleaned the black pins before you popped the sliders back into the board?

 

[clinic-audio]

the shaft is different but this is the same switch

 

[MonkeyRelish]

Did you also cleaned the black pins before you popped the sliders back into the board?

Yes, with a pencil rubber.

Mr Relish

 

[rottalpha]

the shaft is different but this is the same switch

View attachment 1961222

they look new. At the very minimum you could probably use the internal guts to fix one with a kurled shaft, if needed

 

[rottalpha]

Yes, with a pencil rubber.

Mr Relish

 

[MonkeyRelish]

they look new. At the very minimum you could probably use the internal guts to fix one with a kurled shaft, if needed

It’s easy to swap the front section over. Just four metal tabs on the front.

Mr Relish

 

[rottalpha]

It’s easy to swap the front section over. Just four metal tabs on the front.

Mr Relish

???
you would think that Clinic would already know that

 

[MonkeyRelish]

He probably prefers to file the knurled sections by hand

Mr Relish