Help with GE boombox

[Joseph_b]

hey guys,
I'm new here and i have a question about my old General Electric stereo boombox
that belonged to my late grandfather and I'm trying to restore it to working order.

It is a model 3-5284 A , AM/FM stereo cassette recorder.
The problem is both AM and FM are weak. AM reception is almost deaf and FM seems to be out of alignment.
on FM side it has lost sensitivity to the point were it can hardly hear my 3 local stations that output 100 kW located less than 30 miles of me. ( all three stations transmitters are on a mountainside west of me about 26 mi, and transmit 100,000 Watts )
all other radios i house hear these loud & clear but the GE is noisy and staticy. has hard time detecting stereo signal.
I can put my hand on or near radio and it will tune in, but move and reception is lost. Also the tuner seems slightly off scale,
and strong stations are smeared across the dial taking huge space while weaker stations are a blip on the dial.

does this sound like an alignment issue? could it be a component failure like capacitors?
this radio is from early 1980s and has never been worked on. it has also been around a lot of nicotine and cigarette smoke.
I have cleaned all the switches and knobs with contact cleaner which definitely got rid of some noise

 

[73's de Edd]

Sir Joseph_beeeeeeeeeee . . . .

Assuming that you are testing with AC power . . . have you tried battery operation to confirm that the units internal AC to DC power supply may have developed time deteriorated parts . . . .particularly the mentioned quirky images which could be caused by low power supply voltage(s) and / or quirky bypassing in the power supply proper..

DO NOT TURN ANY "loose screws" in the interim, and I will have my #1 son pick up its schematic sheet next time out to the " mule barn " archival storage of ours.

73's de Edd
.....

 

[Joseph_b]

Sir Joseph_beeeeeeeeeee . . . .

Assuming that you are testing with AC power . . . have you tried battery operation to confirm that the units internal AC to DC power supply may have developed time deteriorated parts . . . .particularly the mentioned quirky images which could be caused by low power supply voltage(s) and / or quirky bypassing in the power supply proper..

DO NOT TURN ANY "loose screws" in the interim, and I will have my #1 son pick up its schematic sheet next time out to the " mule barn " archival storage of ours.

73's de Edd
.....

thanks.
i have tried both AC and battery. behavior is the same

 

[73's de Edd]

Sir Joseph beeeeeeeeeee

Phase 2 . . . . .

Of initial evaluative testing would be to get a pre recorded cassette tape and fast forward it and then fast rewind it for enough time to get the old dormant rubber / neoprene a bit warmed up and then chance a play to see HOW the tape player max volume capability seems to be . . . . . as comparing to the duo radios, prior audio performances ?

It has 4 basic supply voltage levels being incorporated.

The RED ARROW 10.8 supply line takes care of your power hungry cassette motor and the sets two integrated circuit audio output stages.
That same feed, then passes down and to the left to the Q5 regulator, to then emerge as the 4.9VDC secondary supply via the BLUE ARROW path.
(Do note that this was probably being the first assignment of some new hire that has ever so dutifully carried his readings to 2 decimal places . . . . so basically expect ~10.5 -----~5V -----~2.4----~ 2.0---~1.5 to be permissible.)
Inside of IC1, there is a regulator stage which outputs ~2.4VDC at its pin 16 as then shows up as the GREEN ARROW path, that
then resistor divides down to the ORANGE ARROW path.
The PINK box notes the 5.6volt zener used for that regulator stage.
The double YELLOW rectangles designate the principal filters used on those 4 supply levels.
Check the RED ARROW supply line and see if that voltage pulls down appreciably when max volume is run up. . or if it holds ?

How are voltages reading . . . .?

Est quidem signum а . . . . .
GENTLY ELECTRIFIED . . . E 3-5284A . . . . . SCHEMATIC REFERENCING . . . . . .

73's de Edd
.....