KLH 20 popping

[montesa]

I posted this already but I can't find it even in the search.
Here goes again. My dad's 1965 KLH model 20 plus works but the source selector and tone controls are terribly scratchy.
A. Is it possible to deoxit them by removing the wood bottom? From pictures online it looks like you might be able to access the source selector and tone controls with the bottom off.
B. The base control is not only scratchy, but moving it slightly creates a very loud popping. The woofer jumps when this happens. Is DC voltage somehow getting through when I move the knob. Does this seem like a more serious problem or should I try deoxit first?
C. I can't find anyone or any shop in LA to work on it. Marconi said they won't. Any suggestions?

D. It sounds great but weak on base. Should I just leave it alone and just not touch the tone controls?

 

[eiraved]

Welcome to AK!!
There's plenty of techs in the Los Angeles area, you should be able to locate one with a Google search. Obviously it would be less expensive to access and work on the controls yourself. Remove the bottom panel of the wooden cabinet and your should be able to access the controls and spray with some DeoxIT D5 (with power off). Work all the sprayed controls fully back and forth about 20x and allow some time for them to dry, then turn the unit on and test. Hopefully the DeoxIT application is enough to remove the offending noises.

 

[Dave1027]

I would definitely deox the bass control (and all controls) first. If the popping remains, that could indicate an issue in the preamp section.

 

[eiraved]

I’m assuming you reside in or near the San Fernando Valley by your choice of Marconi. Here’s a couple more valley choices:
Northridge Electronics in Simi Valley.
The Audio Specialist in Valley Village.

 

[montesa]

I'm in Pasadena. Marconi refused to even look at this. I'll try the deoxit first- actually what I have it nu-trol 401B control cleaner, and if that doesn't work, I'll call the other companies you listed.

 

[rickl]

i'm heading home tomorrow otherwise you could bring it over. i'm by agoura hills on mulholland hwy. i've been here for 3 weeks looking for some gear to work on.

sorry for the worthless post.

 

[montesa]

I used the nu-trol 401b control cleaner on all the pots and source selector switch and it got rid of the scratchiness and popping. Well 95% of it anyway. The caps all looked ok except there was a tiny bit of corrosion on one end of one of them. The preamp board looks like it would be very difficult to remove so I'm going to leave the caps alone for now. The nu- trol didn't really help the power switch, or the mono/stereo switch which are somewhat hard to move and sort of glitchy. Is there a better lubricant for the power switch on the KLH 20? This style of switch doesn't slide smoothly and feels like it's hanging up on something internally.