GF-9090 sliders

[rollcentre]

Has anybody replaced the volume/treble/bass sliders on a GF 9x9x box? is it as easy as de-soldering the contact points of the slider pc board?

I am getting low volume out of my 9090, I can jumper the slider contact to the resistor track on the volume slider and get correct volume, I would like to repair or replace this slider and also the bass slider.

Can these slider pots be cracked open and repaired easily? I found a contact from the bass slider sitting in the bottom of the boombox, i believe the volume slider contact has broken off and lodged in the slider, blocking it from moving

I know the specs of the pot, can a replacement be sourced? Does anyone know a good source for finding these slider pots. I am on the hunt,

Volume slider-(20KbX2) linear taper, 20k ohm, dual resistor track
Bass slider - (100kXb2) linear taper, 100k ohm, dual resistor track

the brand sharp used on this box was ALPS, Sharps part number is RVR-Q0058AFZZ for the volume slider, RVR-P0061AFZZ

Hope i have provided enough info, i would love to get this old box singing again

 

[Lasonic TRC-920]

Have you first tried cleaning with DeOxit?

 

[rollcentre]

Hey Lasonic, I forgot to mention, I did clean all the switches and sliders on the top panel and the record bar with DeOxit...

 

[Fatdog]

Hey rollcentre, first off, welcome to the site!

Did you have the unit open and partially disassembled when you sprayed DeOxit? You can't always properly reach the contacts from the outside of the boombox. Most of the time you have to get to them from the inside.

 

[rollcentre]

Hey Fatdog, Thank you for the welcome

I had the top cover off and also blew out some dust with PC duster gas before spraying Deoxit.

Just yesterday I decided to work again on the box-- I turned it upside down in its disassembled state, gave it a good shake around, and woudnt you know, the slider contact piece fell out of the metal body of the volume slider. It is identical to the one I found in the bottom of the box.. no doubt from the bass slider!

It looks like a real chore to remove the pots from the PCB. I sure hope I can find a replacement that will fit back on the board! If i cant, I guess I will have to rig up a 20kBX2 rotary pot somewhere... wire it to the board and maybe mount on the side panel with the remote and mic inputs.

The bass slider pot i may end up putting a fixed resistor, that would be a bummer though.

 

[rollcentre]

Ok, been doing to digging on replacement pots, After studying the schematics for the slider board, It appears that the volume slider has center taps, probably for the loudness control. I don't see any options for a center tapped slider(a tap in the mid point of the resistor grid)

If I solder in a pot without center taps, I am hoping the volume will operate normally and just not have a loudness control function

 

[rollcentre]

Made some progess on the ol gal over the weekend. A belt kit arrived and I now get motion from the cassette player. This cassette deck needs a full refresh, all of the grease they use on the levers pivots linkages etc, has gone sticky. I fashioned a capstan roller from a silicone tube and seems to work great. The black goo that used to be a rubber roller I flushed out with brake parts cleaner. bushings were lubed. Still needs some points lubed as the cassette speed seems to be dodgy and rollers are sticky. No FF or rewind and the APSS switches are corroded, i need to find a fibreglass bristle brush!

OK anyways here is the innards of the bass slider, as you can see the 3-finger little contact piece is broken off! the other barely clinging. These old sliders are very fragile! the 45 year old plastic keepers that hold the contacts break very easily. I am thinking a bit of JB weld will hold the 3-finger contact back where it belongs. I think these sliders are salvageable,,, which would save me some grief.

Also you can see the volume slider with the center taps! I hope to crack that one open and find it to be salvageable.

 

[rollcentre]

Unfortunately the volume slider is a bit worse for wear, the conductive coating of the resistor has worn thru down to the bare pcb. I will try some conductive paint to touch up the places that are worn out.