How do you open a pot to clean it thoroughly?

Status
Not open for further replies.

Old school Scott

Member (SA)
Yes, after the Deoxit spray and the compressed air.
My volume switch on my Panasonic 5150 is still scratchy.
I have to go in, but how?

Cheers OSS :afro:
 

baddboybill

Boomus Fidelis
Old school Scott said:
Yes, after the Deoxit spray and the compressed air.
My volume switch on my Panasonic 5150 is still scratchy.
I have to go in, but how?

Cheers OSS :afro:
For the most part there are maybe 4 tabs holding it closed. It may need more than cleaning though. You may be able to ship pot to Norm. He has fixed mine and does great job :thumbsup:
 
baddboybill said:
Old school Scott said:
Yes, after the Deoxit spray and the compressed air.
My volume switch on my Panasonic 5150 is still scratchy.
I have to go in, but how?

Cheers OSS :afro:
For the most part there are maybe 4 tabs holding it closed. It may need more than cleaning though. You may be able to ship pot to Norm. He has fixed mine and does great job :thumbsup:
Wait, you can now ship pot in the U.S.??? :lol: :weed:
 

baddboybill

Boomus Fidelis
Strānj-Bōōmbŏks said:
baddboybill said:
Old school Scott said:
Yes, after the Deoxit spray and the compressed air.
My volume switch on my Panasonic 5150 is still scratchy.
I have to go in, but how?

Cheers OSS :afro:
For the most part there are maybe 4 tabs holding it closed. It may need more than cleaning though. You may be able to ship pot to Norm. He has fixed mine and does great job :thumbsup:
Wait, you can now ship pot in the U.S.??? :lol: :weed:
Why yes didn't you know we are a free country :w00t: As long as we pay super high taxes ;-)
 

alfie

Member (SA)
Strānj-Bōōmbŏks said:
baddboybill said:
Old school Scott said:
Yes, after the Deoxit spray and the compressed air.
My volume switch on my Panasonic 5150 is still scratchy.
I have to go in, but how?

Cheers OSS :afro:
For the most part there are maybe 4 tabs holding it closed. It may need more than cleaning though. You may be able to ship pot to Norm. He has fixed mine and does great job :thumbsup:
Wait, you can now ship pot in the U.S.??? :lol: :weed:
:lol: :lol: :lol: :lol: :lol:
 

Reli

Boomus Fidelis
baddboybill said:
Old school Scott said:
Yes, after the Deoxit spray and the compressed air.
My volume switch on my Panasonic 5150 is still scratchy.
I have to go in, but how?

Cheers OSS :afro:
For the most part there are maybe 4 tabs holding it closed. It may need more than cleaning though. You may be able to ship pot to Norm. He has fixed mine and does great job :thumbsup:
Bill, when you say tabs, can you elaborate? Here is a photo I took (GF-8989 volume and treble knobs). Obviously, spraying deoxit from the front side won't accomplish anything, right?

dsc05954.jpg
 

kingrat2010

Member (SA)
maybe im ignorant but i think u can spray into the little holes next to the pots, left side from the silver one and the little hole underneath the golden one :hmmm:
 

Reli

Boomus Fidelis
kingrat2010 said:
maybe im ignorant but i think u can spray into the little holes next to the pots, left side from the silver one and the little hole underneath the golden one :hmmm:
I think you're right about the gold one.....I can see rotating parts in that hole......But the hole by the silver one is no good --- it does not lead to the inner workings of the pot
 

mmcodomino

Member (SA)
So far I was able to clean the scratchiest pots with contact spry always from the front. Wiggle the stem of the pot and turn it around many times. Don't be worried about using too much contact cleaner. There is a limit but I never screwed up using too much yet :lol: .
Really, contact cleaner causes miracles on some boxes.

OSS - maybe just try again with contact cleaner and move the stem in the pot up and down and push it to the left and right side while turning. That oftenly helped with very bad cases for me :yes: .
 

docs

Member (SA)
I had a similar issue with the volume control pot on my 9797.
After tracing through it all diagnosing where the problem was, I found that in an absolute minute area on the volume circle the dead channel sprung to life.

I took pictures of the pot and how I repaired it to restore sound perfectly.

I'm not sure if a slider is similar to a volume pot but it may be of help, if not apologies.

Heres the info.

I noticed on the 9797 the sound on the left channel was pooped. So I set about opening it up and checking the usuals, connectors and continuity across the speakers etc. The only thing I had noticed is that the volume knob was very loose and didn't really have any friction to it. I was suspicious of this but didn't think it was the root cause, silly me.
Checked the amp chip by jumping the left and right pins and wallah sound came out of the left channel so amp chip was good. Could it be in a more awkward place ? I had to remove the entire board section to get at it from underneath, painful.

P1020728.jpg


So, thinking the problem lay further towards the input I bought a signal injector and started to put that together so I could inject a signal along the various points to see where it was failing. At the same time for whatever reason I hadn't before, I turned the volume to full while listening to white noise from the radio and noticed that there was a tiny 1mm section that actually made the left speaker come into action! DOH!

P1020758.jpg


So I set about getting the board out with the pots on it, which is a complete ballache. Opened the pot which is held closed with 4 little angled clips underneath to reveal the brushes.

P1020769.jpg


In the pic you can see there are 2 brushes. The inner and smaller one was loose when I opened it and you might just be able to tell that all the brush ends were bent and a bit shot. So I simply cleaned this section up and checked the contact side and proved that there was continuity throughout and give them both a good clean, they were covered in too much grease.

P1020774.jpg


After useing a bit of super glue to reseat the smaller brush and straightening out the brush ends as best I could before going completely bogeyed, it looked in good shape again.

P1020776.jpg


P1020778.jpg


Left it to set for an hour or two and set about putting it back in the board and the board back in to be able to do a test.
Plugged it in and set to radio and the volume was really low, full whack on the volume and could barely hear it. BALLS! what have I broken now?
The board with the pots on it has a ribon cable that solders directly into the board and connects to the main pcb underneath the tape deck. These are usually secured in place with a touch of glue to the pcb where it is soldered to take the strain off the soldered joints. Needless to say the glue had long since gone and as a result 3 or 4 of the 8 pins had disconnected. Restripped the ribbon, desoldered the underneath of the board and resoldered each wire on the ribbon back into place. Continuity test showed it all to be good.

P1020783.jpg


Reseeated the board again and did the test.
PERFECT !!!!!!
Audio is even out of both speakers!!!!
I love it when a plan comes together and with a little patience.
 

Reli

Boomus Fidelis
Great post, docs! I had no idea what the backside of those things looked like! Who knew they actually had brushes. :hmmm:
So you simply bend those 4 tabs holding it to the board, in order to pull it off?
 

docs

Member (SA)
Hey Reli, yes that is what i did but you have to be ultra careful as they can easily snap off.
 

snarfeater

Member (SA)
thats easy just use a small flat screwdriver to bend open the tabs and get alcohol on a swab and swab the black resistor surface until the swabs are not black anymore then make sure its dry then get dielectric grease to protect the black surfaces from wear then close it back up thats all :yes:
 

docs

Member (SA)
snarfeater said:
thats easy just use a small flat screwdriver to bend open the tabs and get alcohol on a swab and swab the black resistor surface until the swabs are not black anymore then make sure its dry then get dielectric grease to protect the black surfaces from wear then close it back up thats all :yes:

Ofcourse... Thats why I took the time to photograph it all and help with good descriptions...
 
Status
Not open for further replies.