Sharp GF-7400

Hi all,

I've recently reacquired my childhood boombox, an early to mid 1980's Sharp GF-7400 and despite spending over 20 years in my fathers' shed, is in pretty reasonable condition.
After a quick clean up of the exterior cabinet, tape head, pinch roller and tape path and inserting new batteries the radio works fine and the sound is full and well balanced between the 2 speakers, but there was almost no audio from the tape deck. The muffled sound got lower over about 30 seconds until just background hiss could be heard. Listening to tape through headphones, the audio is there but volume is low, much lower than radio.
I tried recording from radio to tape and surprisingly when I played the tape back on a Walkman the sound was ok, a bit imbalanced but not terrible.

I'm going to dismantle it and give it a good clean and inspect capacitors, clean switches etc but would be interested to hear if anyone has ideas what the fault might be. Thanks...

 

Thanks Mister X. I'll give it a try tomorrow. Not sure why that would cause it but if it's a common fault it's definitely worth a go.

 

There will also be a large internal slide switch that is used to switch between play and record functions which might need cleaning

 

A quick update on my issue. I liberally sprayed the source switch and internal record switch with contact cleaner and exercised both manually many times and I'm happy to say I now have some audio coming through during tape playback but it is at a much lower volume than expected. Both channels are about the same level, but I need to raise the volume control to 4 when the radio only needs to be at 2 for the same volume level.