Volume Problem - Please Help...

[[email protected]]

Hey gang! Lately, at a thrift store, I picked up an old 80's GE Radio
with AM/FM/VHF High bands. I've salvaged a few radios before, but this
one has me stumped. I turn it on and on all bands, the sound is VERY
low at the maximum volume. I shot some contact cleaner into all the
controls, and still nothing. I mainly picked up the radio because it
was a small one that also had the VHF high band.

I did open it up in the back to check the battery contacts, and someone
had left old batteries inside and it was a mess. Needless to say, it
was such a mess that it had pretty much destroyed the contacts, but
this one runs off AC as well. I checked inside and it was made in 1984.
Does anyone have any idea what could be wrong here?

I'm just a beginner here, but would like to fix it possible.

Jim

 

[Travis Jordan]

I'm just a beginner here, but would like to fix it possible.

Power supply problem?
Bad speaker?
Corroded headphone jack?
Open audio coupling capacitor?
Leaky bypass capacitor?
Resistor changed value?
Semiconductor open / shorted?

Have fun.

 

[Phil Bowser]

I'd start looking for an open electrolytic coupling capacitor in the
final output stage. Is there one in series with the speaker, like 1000uF or
so? In a very Low-power application, it could be as low as 100uF, I
suppose...

 

[Asimov]

"[email protected]" bravely wrote to "All" (18 Feb 05 11:47:17)
--- on the heady topic of "Volume Problem - Please Help..."

ra> From: [email protected]
ra> Xref: aeinews sci.electronics.repair:10882

ra> Hey gang! Lately, at a thrift store, I picked up an old 80's GE Radio
ra> with AM/FM/VHF High bands. I've salvaged a few radios before, but this
ra> one has me stumped. I turn it on and on all bands, the sound is VERY
ra> low at the maximum volume. I shot some contact cleaner into all the
ra> controls, and still nothing. I mainly picked up the radio because it
ra> was a small one that also had the VHF high band.

ra> I did open it up in the back to check the battery contacts, and
ra> someone had left old batteries inside and it was a mess. Needless to
ra> say, it was such a mess that it had pretty much destroyed the contacts,
ra> but this one runs off AC as well. I checked inside and it was made in
ra> 1984. Does anyone have any idea what could be wrong here?

ra> I'm just a beginner here, but would like to fix it possible.


Jim,

Since you mentioned it had batteries it reminds me of a portable
sw/vhf receiver I repaired this fall with similar symptoms, very low
volume. It turned out a solder joint had broken around a resistor leg.
Try signal tracing from the volume wiper.

A*s*i*m*o*v

.... Modulation in all things...