Technics SA-424 Receiver

[RKENDALL]

Hello,
I have an issue with a 1981 Technics SA-424 receiver, concerning the tuner section.
When I initially turn the receiver on and have it in the tuner mode, it will not have the quartz lock and the FM stereo lights or audio working. Just silence?
It works fine in mono upon powering it on, but no FM stereo or quartz lock working.
That is until about approximately 15 minutes have past, and then it is working perfectly in FM stereo, along with the quartz lock light on, and perfect audio in stereo.
I've cleaner this unit multiple times with Deoxit D5, faderlube, and just tried some CRC contact cleaner.
I've tried the tape outputs, along with the Aux, and it played a tape and CD perfectly.
The only issue I'm having is the unit not initially starting up in FM stereo when powered on?
Only after is has been running awhile, and warmed up, that it will lock onto FM stereo audio perfectly.
Thanks in advance for any suggestions on solving this issue.

 

[DaveVoorhis]

Possibly a cracked or cold solder joint on the circuit board, or a failing integrated circuit or other component. You may be able to find it by letting it run until FM stereo works, then gently prod all the tuner components with the eraser end of a pencil or (better) spray them with freeze mist. When the FM goes off, you've found the problem.

 

[RKENDALL]

Hello,
well I tried what you suggested, but couldn't find any issues with solder joints or anything?
I adjusted the VCO VR301 pot, and that helped in getting the synth light to illuminate, along with locking into stereo FM mode.
tI still is hit or miss though, whether it is going to work correctly or not?
I recently read somewhere about readjusting the AFC coil? Is that something I can do myself without some type of specialized tools, and if so, where would I locate it to adjust it, and how is the best way to make the adjustment?
Also just read how a basic rabbit ear antenna would help boost the FM reception to the receiver? going to try that tomorrow when I get the rabbit ears.
Thanks.