Technics volume pot frozen?

I think I may have froze the volume pot in my Technics SA-5460. I spayed some contact cleaner into it, and I was cycling it around and suddenly it froze and became immobile. I've tried pulling the knob off and moving it with pliers and its extremely difficult. What did I do wrong?

crazyjeeper said:

I've tried pulling the knob off and moving it with pliers and its extremely difficult. What did I do wrong?

Click to expand...

That.


That cleaner does not come out cold and should be safe on most plastics. But you could have broken a plastic piece inside the pot.

That said. Get some De-oxit.

Rob

So at this point, replace the pot?

I suspect that the original lube used to make the pot feel extra smooth has now become your enemy. It will be on the shaft and the pot housing that goes through the chassis. I doubt there is really a problem with the wiper and carbon track inside the pot itself.

I've had this problem but with a 60s vintage McIntosh MX-110. Attempting to turn it after it started freezing up only made things worse.

Here's what I did to get it going:

- Pulled the front panel as they're NLA and gave me more work space without collateral damage risk.
- Stood the unit up on its back so that the front faces up. This allows you to use gravity for the next step.
- Used a light penetrating oil - a couple of drops actually - and let it stand for a day or so. I put these drops right onto the seam where the shaft exits the pot housing. Yours might not take as long but don't push it.
- A couple of more drops went into it the next day.
- Then, I used the pliers to see if the shaft had become any more pliant. A couple more drops went in.
- Finally, it broke free but a lot of gunk then had decended into the pot housing. I used FaderLube to flush it out. I did this with the opening of the pot facing down so that the gunk ran out. I did _not_ run the wiper any more than I needed as I didn't want that gunk to contaminate the wiper's carbon track any more than I could help.

The pot will likely feel different when you're done as the silky feel will be gone - but you'll have your pot back.

Hope that helps.

Cheers,

David

Well, I'm going to try David's method.

Also, there was no silky feel to start with, it was very hard to turn anyways and the right channel was extremely noisy and often would cut out.

Edit: David, what did you use for penetrating oil?

Also, how big of a job is it to replace the pot assuming I can find one?

Edit 2: New development:
I pulled the nut off on the front of the pot and it now rotates easily and I can easily hear and feel each click detent. However, the shaft is frozen to the threaded bit, so I think David's theory is correct, I just need the right lubricant to loosen it back up.

PB Blaster is probably the best penetrating oil I've ever used. Use it sparingly. When you are flushing the pot,I'd use D-5 to flush it out and THEN hit it with FADERLUBE. A LOT OF FADERLUBE.

On the Sub I volunteer on one of the Main induction valves in the Fwd Engine Room was froze up tight in the open position. We run our commercial A/C supply into the boat's ventilation system thru this valve. 18" valve, with a 4' operating lever. We sprayed the bejesus out of everything on the valve, and linkages, and let it sit for a day. Came back the next morning and got MONGO(our Gargantuan Torpedoman) on the Op lever. Mongo took hold, grunted twice and the valve broke loose. We then put all the grease fittings back in and hit them all with a mix of Marvel mystery oil and the Grease thru the greasegun. The valve now works like it was new. The last time we can document this valve as operational was 1971. And we got it working last October.

Larry

I tested the pot to make sure it still works, and the right channel is still really inconsistent and scratchy. At this point, I'm really close to just finding a hi-fi shop here in Dallas and taking it in.