I had the wire clipped to the balance lead that I de-soldered from terminal E. Now when I do the test I get one side is normal the other tone module has flat out loud volume that cant be turned down and the balance wont work either? Sorry about the balls up.

 

Now you've lost me again.

I am trying to ascertain that the LEFT channel VOLUME control, TONE MODULE and DRIVER MODULE are operational.

Ignore the BASS, TREBLE and BALANCE controls for now.

 

Now you've lost me again.

I am trying to ascertain that the LEFT channel VOLUME control, TONE MODULE and DRIVER MODULE are operational.

Ignore the BASS, TREBLE and BALANCE controls for now.

The left channel volume control,tone module and drive module are operational. If I leave the alligator clip on E terminal on the left driver module and change the other end to R28 on other tone module I have no control at all of the balance and volume, the volume is flat out loud.

 

Well, I stuck with it and found what the problem was. It was two 100nf poly capacitors next to each other on the left tone module that had been installed the wrong way,they had been crossed over with each other?One pin from each cap was in the others pinhole? It must have been made on a Monday? LOL It has been this way since 1967, since it was new? I couldn't really tell by looking at them and I took it for granted that they hadn't been touched but poking around with an oscilloscope told the story. I would never have thought that two crossed over poly caps would show such confusing symptoms? But there you go,a bit more to put down to experience. Thanks for the ideas and suggestions fellas it all helps.

 

Well spotted. Glad the problem's solved.

It has been this way since 1967, since it was new?

Surprising the original owner didn't return the radiogram to the supplier.