help w/diagnosis - input selector knob or input? [Archive] - Audio & Video Forums


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05-01-2012, 11:04 AM
One of the inputs on my Jolida 202A integrated amp is making a crackling sound in one channel and sometimes the sound just drops out of that channel. I can move the selector knob within the setting for the input and it clears up. I haven't run too many tests yet like using a different component in the input or moving the component that uses the input to another input because it seems like the problem is with the input selector knob (but only in that one position). The Jolida is not known for its vast array of inputs. I pretty much need all of'em. Any suggestions on where to begin in diagnosing the problem and perhaps fixing it myself?

The volume and input selector knobs are attached to turning shafts with socket or allen head screws. The face plate is attached with the same kind of screws. I assume I need to remove the knobs then the face plate to check the connections to the input selector? Then, what do I look for? Or, how do I tell if something ain't right?

Be kind. Help a DIY dummie.

Glen B
05-08-2012, 11:53 AM
Before you disassemble anything, try spraying some DeoxIT contact cleaner into the input selector switch and rotate it back and forth several times. If that does not cure the problem, check for a bad solder joint. If after that you don't find anything amiss, then you may just have a bad selector switch.

DeoxIT spray (

05-08-2012, 03:13 PM

There is an outside chance that a tube on one side could be bad.

05-10-2012, 08:09 AM
Thanks, guys. I picked up some Deoxit yesterday, but won't be able to try it until the weekend. I thought it was the tube in my Bellari phono stage that occupies the input at first then ruled it out after swapping in several and noticing that fiddling with the selector knob effected the crackling sound. I don't think it's a tube in the amp because all other inputs work fine. I'll double-check, try different sources in the input and use the Deoxit.