Bass circuit problems on model 38-690

[flradiodoc]

I am restoring a 38-690 and am having a problem with the bass amplification system. The chassis has been completely gone through and plays great. Only problem is the bass control does not do anything at all when adjusted. I have chased electrons until I am blue in the face and have gone over everything numerous times to see if I can find the problem, but to no avail.
If anyone out there can help me on this one, thanks a bunch.

Mark...

[7estatdef]

Hi Mark
I took a quick look at the diagram and my hair instantaneously burst into flames!!!! A poor of a rendering of the diagram on NA very hard to follow! Generally I would check the pot for shorts to the chassis break out the Signal tracer and start at the pot and nose around a bit to hear if there is any bass boost. Key suspects would an open resistor or cap. I know it's not much to go on.
Terry