Sharp GF-9191

[Fatdog]

I thought I would go ahead and post a thread here while I wait for a service manual in the hopes that someone else has encountered - and fixed - my problem before. I'm restoring a Sharp GF-303SG that is basically the Japanese domestic version of the Sharp GF-9191.

Everything works on the boombox... except STEREO.

The switch that operates MONO / STEREO / WIDE works perfectly in MONO and WIDE. However, the right channel is almost completely dead in STEREO. When turned all the way up, you can barely hear the sound for the right channel.

Speakers - I get left channel only - while in STEREO

Headphones - I get left channel only - while in STEREO

VUs - Both channels are bouncing normally in all modes

Line Out - I get perfect stereo

By the way, I DeOxited the entire box and nothing has changed.

Has anybody else encountered this problem? Or maybe have a clue as to what happened?

 

[baddboybill]

Bobby have you checked all solder joints on switch or maybe inside of switch has bad contact point

 

[Fatdog]

If only I could get to the switch! That thing is packed on the board tighter than... well... you can probably guess. Every solder point on that board is separated by only about 1mm of space. Plus, I'd have to cut about 30 wires just to get the board out. I do have replacement board from Blasterpunk that I could use. BUT... I'm not 100% certain that the problem is localized to the board.

 

[71spud]

Maybe.....

 

[chevyman-uy]

I have it a similar problems in my GF 9090 ,i take a look in the weekend ,

 

[MasterBlaster84]

I have it a similar problems in my GF 9090 ,i take a look in the weekend ,

Same here, haven't yet got around to checking it out. Sounds like this might be a somewhat common problem with these GF's.

 

[Superduper]

Don. The 9090 and 9191/9292 are different enough to affect troubleshooting in that the 9090 has a single volume and separate balance control while the latter has dual volume controls. One channel is dead, that is fer sure. The only question is where is the break in the audio signal leading up to the amp, which I've concluded is good.

 

[Sainthonore]

Right Channel Fault
Hi a bit of an ancient post but my reply may be of use to someone. My GF9191 worked in mono, worked in stereo wide (but the right channel sounded weaker) and in stereo left channel worked but right channel hardly any volume at all. Anyway I fixed the fault by replacing the top board with the four toggle switches on with a known good board and now the GF sounds great in all modes.I didn't suspect the switch as I was getting at least something from the right channel in stereo and wriggling the toggle on the switch made no difference. There's a cluster of capacitors surrounding the switch so it's likely one of them was causing the problem. By the way it's a good idea when working on this board to wrap a bit of card over the tuner needle cord. I accidentally touched it with the soldering iron and it pinged apart (something else I need to fix now).
PS The photo is of the good board. It shows a couple of caps missing on the left which I replaced and they're unrelated to the right channel fix.

 

[Ghettoboom767]

I have 2 9191's and one of them has this same problem!😮Someday I'll tear into this or try replacing the top board.