Sharp GF-9090 - in over my head.

Osysix

New Member
Oct 5, 2022
2
0
1
UK
Hi, long time lurker, first time poster here.

I've recently decided to start on my completely amateur restoration of a Sharp GF-9090 I acquired years ago.

The current state of play is a complete (and thougherly terrifying) teardown, the plastics are drying after their bath and I'm recapping and switch cleaning. I've got some belts coming and luckily the pinch roller and idler tire seem fine.

I've got a couple of issues that I need help with though and I figure you guys are the ones to ask.

Firstly, and most upsettingly, I need to replace the tweeters as when I was removing them from the front of the case the connections came away at the slightest touch. The voice wires are no where to be seen and I think they've corroded and the end has disappeared inside. I've had a dig around but I don't think they're salvageable.

I've had a look online for suitable replacements but I'm over my head with the options. The originals are 4ohm 3.5-5w dome speakers measuring 2cm at the point they drop into the case.

The second problem I have is a very weak single on the left channel when the mode switch is in the Stereo position. Mono works and Stereo Wide kinda works but the left is still slightly weaker. I've cleaned said switch but I don't think that's the problem. I'm hoping recapping will help (I'm currently doing it in sections in the hope I won't have to do all three boards in their entirety)

Does anyone have any hints on how to narrow down the issue?

Apologies for the long post and many thanks in advance for any assistance offered.
 
Last edited:

Northerner

Member (SA)
Apr 16, 2012
5,325
256
83
North West UK
Had that issue with 9090 tweeters before. Seemingly no way to reattach the wires. As for the dodgy channel you need to clean the full audio path; headphone socket, record bar etc as it could be anywhere along it. Then see what happens :-)
 

hopey

Member (SA)
Dec 28, 2014
1,298
292
83
Melb AU
That's a great radio I have a couple that have pre amp issues I have heard that there can be open circuits on the PCB good luck with that one.

Since you have it apart I would strongly recommend rebuilding all the pots. It the only way to eliminate faulty contacts inside the sliders (you can pinch parts from the REC sliders). Rebuild the function switch as well.
 

Daeljan

New Member
Jan 19, 2020
10
1
3
Hi, I'm in the same boat with my tweeters, and I'm looking for alternatives. Nothing concrete yet but its looking like I'll end up having to mod the case somehow to get a replacement to fit. If you did find some replacements I'd love to know what you did! Thanks.
 

Daeljan

New Member
Jan 19, 2020
10
1
3
Had that issue with 9090 tweeters before. Seemingly no way to reattach the wires. As for the dodgy channel you need to clean the full audio path; headphone socket, record bar etc as it could be anywhere along it. Then see what happens :-)
Hi, how did you get around this tweeter issue? If you replaced them, what with? If you repaired them somehow - how?
Thanks, just I'm in the same boat atm...