Zenith 10S690 Volume Control Issues

[vortalexfan]

Originally Posted by old_coot88

There's nothing associated with that circuit that should draw any current to speak of, let alone enough to melt solder. Anyhow, check for solid continuity (zero ohms) from C11 to where it connects to the IF can, and to the 1 meg resistor (R11).

From the other side of C11, check for continuity to the top lug of the vol control.

There's gotta be an open on one side or the other of C11.

Doubtful, but maybe the cap itself has gone open(?)

Well I kind of lied about that capacitor being unused, (actually it was more like I forgot) it was used as a DC Blocking cap for my Signal Generator, but I wouldn't think that that would cause the capacitor to fail prematurely, if that's actually what happened here...

[vortalexfan]

I have a .047 MFD capacitor, would that be ok in that spot if it turns out that the .01 capacitor did end up going bad?

[old_coot88]

It'd work, but with excessive bass.

But by all means, first check continuity as suggested, from C11 to where it enters the IF can, and to resistor R22. And from the other end of C11 to the top of the vol control.

Measure from right where the leads exit the capacitor body

[vortalexfan]

Originally Posted by old_coot88

It'd work, but with excessive bass.

But by all means, first check continuity as suggested, from C11 to where it enters the IF can, and to resistor R22. And from the other end of C11 to the top of the vol control.

Measure from right where the leads exit the capacitor body

OK so everything checks out, according to what you said it should check out, nothing is measuring open from what I can see anyways.

I don't know if this would cause a problem or not but one of the wires coming out of one of the IF cans has crumbling rubber insulation and it does have some exposed wire although it's not touching anything.

[old_coot88]

Not sure what O.L. means. But if you suspect the capacitor, just parallel your .0033 and .0047. That'll make .008 which will give a tad less bass than the .01. Be sure and test the caps first.

[vortalexfan]

Originally Posted by old_coot88

Not sure what O.L. means. But if you suspect the capacitor, just parallel your .0033 and .0047. That'll make .008 which will give a tad less bass than the .01. Be sure and test the caps first.

O. L. is overload or out of range according to my manual for my digital multimeter.

Going between the side of the capacitor that attaches to the side going into the IF can and R22 I get 2.5 Meg, and then from the same side of the capacitor to the lower volume control lug (B- lug) I get the same reading 2.5 Meg, and then from that side of the cap going to the IF can to the top lug on the volume control I get 0.3 Ohms.

[old_coot88]

Just need to verify solid continuity (zero ohms) as indicated by the red lines in the shetch: