Sharp GF575 left side audio is quiet

[Jud55]

I purchase this about 6 years ago and had it stored in the loft and im pretty sure it worked fine before putting it away
I came across this thread here

HELP WANTED ! Sharp GF-555. NO voice / sound on left speaker ??? Right one works

Hi there! I have an issue on my Sharp GF-555 boombox. The right speaker works as a charm (and also bass & treble works), but does not give any sound from the left speaker ? Right / Left slider don´t make difference, only sound goes mute if i turn slider totally left (only very very low volume...

www.boomboxery.com

Mine is pretty much the same except there is volume to a small degree, im no expert in any type of electronics , would cleaning the slider be a good place to start if so what do i need to buy to do it, its on all the functions as both tapes do it and so does the radio.
Thanks

 

[Superduper]

I suspect it’s far more likely that the record/playback switch is oxidized and dirty.

 

[Jud55]

I suspect it’s far more likely that the record/playback switch is oxidized and dirty.

Thanks for the reply, did i mention that the audio is the same using the radio? wouldnt this point to something else?

 

[BoomboxLover48]

Lots of connections pass through that record/playback switch. Radio might work then tape, line in and other functions might not. So, it is likely that switch dirty and oxidized like Superduper mentioned.

 

[Jud55]

Got ya, sorry for the dumb question but what part are you referring to by "record/playback switch" and what would i need to clean it, or is it a case of swapping it?

 

[Jud55]

I think i have found it. is this correct

 

[Superduper]

Yes, it is a long bar shaped switch, typically on the main circuit board. Clean by orienting the boombox so that the switch is pointed North/South. Spray deoxidizing electronics cleaner into the top end while actuating the switch to allow the solvent to work its way down and through the switch. The switch is spring loaded and may need to be moved scores (50x or more) for thorough cleaning. Blot up excess solvent when done and allow to dry before powering up.

 

[Jud55]

Yes, it is a long bar shaped switch, typically on the main circuit board. Clean by orienting the boombox so that the switch is pointed North/South. Spray deoxidizing electronics cleaner into the top end while actuating the switch to allow the solvent to work its way down and through the switch. The switch is spring loaded and may need to be moved scores (50x or more) for thorough cleaning. Blot up excess solvent when done and allow to dry before powering up.

Just waiting on some cleaner spray to arrive, i will update once it does thanks

 

[Jud55]

Success, so glad you guys are around, it saved me £125 that i was quoted to get it repaired.

Now its time to install a BlueTooth unit, I have already worked out how to fix it in place and as it goes into pairing mode when powered on that saves fitting a pairing button.

 

[Jud55]

Ok so I worked out how to fit BT to the unit, i do have a buzz that is mentioned in the video, a quick google gave me a few ideas, I think i need a b0505s Isolated Dc-Dc Convertor as im pulling power from the mainboard, it initially was running from a USB power bank and i had no buzz so im guessing thats the reason.
Any suggestions are welcome as these parts are designed for breadboard application but i would prefer something that i can put inline (like the buck convertor i used).

 

[goodman]

Yes, I guess this b0505s Isolated Dc-Dc Convertor will solve the problem.
If you are going to use this Sharp at home connected to the AC,
you can try to power the BT module with a regular phone charger.
The AC of the charger is connected with cables to the AC input of the transformer.
The output of the charger to the BT module.

I use this method in my modded Sanyo C30 here:

Sanyo C30 - restoration & modification

You know that I love to repair and restoring boomboxes from time to time. Here's the story of this Sanyo C30: A friend of mine bought it this summer with the intention of restoring it. The main problem is with the tuner - it does not accept the FM stations well. My friend understands from...

www.boomboxery.com

On the left is the MP3 module, in the middle is the phone charger connected to the AC of the main power supply, on the right.
I even put a switch to turn it on when I use it.


Sanyo C30 - 08 by ivosn