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USSEnterprise
April 20th, 2006, 10:25 PM
I have an old Fisher stereo system, about 20 years old, but the amp if very powerful. Only problem is a dirty balance pot. Problem is, I can't remove it, and its about 4 times smaller than that of an Atari Paddle. How can I clean this? WD-40?

alexkerhead
April 20th, 2006, 10:35 PM
You will need some electrical contact cleaner. WD-40 will conduct electricity, bad.
Spray the electronic contact cleaner into the tiny gap between the stem and cup, and turn the knob back and forth until it works.
I had todo this with my vintage audio system several times.
I use a pioneer sx-1250(one of the most powerful amps ever built, rms) 160rms wpc.
With my JBL L100s, and Pioneer CS-77s, teac 4010 r2r, pioneer pl-530, etc.

USSEnterprise
April 20th, 2006, 10:56 PM
Contact cleaner? Wow. I think I have that. I used it to almost make my pinball machine burst into flames. Thanks.

nige the hippy
April 21st, 2006, 02:20 AM
Hello,

Inclined to disagree with alexK. :bomb:

WD40 IS the stuff to use, you can use it on high voltage electrics (e.g. car ignition circuits) to stop them flashing over, it's a pretty good insulator.

The reason why I would shy away from contact cleaner is that it tends to de-grease what you spray it on. The tracks of pots are lubricated, if you remove that lube, they wear away pretty quickly. The WD (and some rapid wiggling) will tend to flush away the contaminant, but leave some grease.

When I used to work for a well respected guy fixing pro audio equipment, we used to see the results of contact cleaner on pots all the time. on a mixing desk it got expensive!

If the WD doesnt work after a few tries, then try contact cleaner / spray-isopropanol and re-grease the pot with a light NORMAL grease.

We used to have a phrase, "if it should move- apply WD40, if it shouldn't- apply evo-stik!"

Nig

alexkerhead
April 21st, 2006, 05:16 AM
WD40 is nothing but a degreaser, does not remove grime and such.
Here is what you need.
http://www.computercleanusa.com/products/getprod.asp?product_id=CONTACTCLEANER

80sFreak
April 21st, 2006, 05:27 AM
Another thing that works good and IIRC is recommended for Atari paddles is this: http://www.radioshack.com/sm-tv-tuner-control-cleaner-and-lubricant--pi-2103700.html

Cheers,

80sFreak

alexkerhead
April 21st, 2006, 06:11 AM
That stuff leaves a bit of residue however, I used some from a local radio shack on my Sherwood reciever for my bose 301s, and it got scratchy again in two weeks. Opens the tuner box up, and there was yellowish residue left behind.

Terry Yager
April 21st, 2006, 06:33 AM
I think the tuner cleaner is the right stuff to use. The solvent in it evaporates quickly, and leaves behind a light lubricating coating.

--T

USSEnterprise
April 21st, 2006, 07:53 AM
"Blow-off" is what I have. When I cleaned my Atari Paddles, I just opened the pot, dipped the whole thing in isopropyl alcohol, and let it sit for a few hours. Now, with the grease that was still in the metal part, they work fine.

DimensionDude
April 21st, 2006, 02:47 PM
Good thing you spelled out "potentiometer" and didn't shorten it to pot, otherwise we may have had some discussion about LP covers and seeds and such :wink:

Kent

USSEnterprise
April 21st, 2006, 03:17 PM
I always spell it out now, or at least, at first. This was after some confusion with my mother...