What commonly causes panel-switch noise? I just brought home a NAD 7020 receiver that looks like it just came out of the box. I fell in love with the sound. I then opened it up and gave the switches a thorough going over with electronics cleaner and a mini-vac. Very gently cleaned everything else of dust and put'er back together. Volume and balance scratchiness were eliminated.
During a very careful audition I noticed a faint ragged cutting out in the left channel and my heart sunk. I was just starting to think I'd be problem free.
As I eliminated possibilities, I noticed that moving the Selection rotary switch very slightly produced the cutting out. If I held it between stops (between aux and phono) it played solid and clean. The phono detent does something similar. FM Mute, FM, and AM are fine.
Now, I understand pretty well how mechanical volume and balance controls can get noisy due to their construction. But a selector switch should either work - or not. Right? Should I attempt to take it apart?
This would be a huge pain in the *** because the switch is small and connected to the board.
Any magic bullet cleaners you can recommend?
During a very careful audition I noticed a faint ragged cutting out in the left channel and my heart sunk. I was just starting to think I'd be problem free.
As I eliminated possibilities, I noticed that moving the Selection rotary switch very slightly produced the cutting out. If I held it between stops (between aux and phono) it played solid and clean. The phono detent does something similar. FM Mute, FM, and AM are fine.
Now, I understand pretty well how mechanical volume and balance controls can get noisy due to their construction. But a selector switch should either work - or not. Right? Should I attempt to take it apart?
This would be a huge pain in the *** because the switch is small and connected to the board.
Any magic bullet cleaners you can recommend?
Hey Dude,
Consider this, cleaners don't really clean anything... they just move the gunk somewhere else really... you may have had a droplet settle on that switch postion. sme cleaners actually carry things away but they are all illegal now I think. Try spraying that thing again but this time while you're moving the switch back and forth until it dries.
Just a thought,
Consider this, cleaners don't really clean anything... they just move the gunk somewhere else really... you may have had a droplet settle on that switch postion. sme cleaners actually carry things away but they are all illegal now I think. Try spraying that thing again but this time while you're moving the switch back and forth until it dries.
Just a thought,
In the days of dual-standard TV sets, the standards switch (which worked in much the same way) was probably the most unreliable component in most sets. A good clean with solvent and - the important bit - vigourous operation, almost always solved the problem.
The trouble is that the contacts are designed to be self-wiping, but if the switch is rarely operated, they can't do much in the way of self-maintenance.
The trouble is that the contacts are designed to be self-wiping, but if the switch is rarely operated, they can't do much in the way of self-maintenance.
dnsey, you may be on to something there. I've often wondered why it's the speaker selection switch that people often gripe about "going out" first. For most users, it has to be the one that sees the least use.
I guess I'll have to really blast it with cleaner and try to get the vac nozzle near to it.
Anybody have suggestions for a killer solvent to use here judiciously?
I guess I'll have to really blast it with cleaner and try to get the vac nozzle near to it.
Anybody have suggestions for a killer solvent to use here judiciously?
No flame throwing here. It's all I ever use for switches and pots. Rotary or slider, works like a charm.
Thanks for allowing me to come out of the closet.
My name is Cal and I use WD40.
Warning: This cleaning is done by professionals on a closed course. Do not attempt this at home. Actually I have no idea how bad it is but I have many, years old gear that hasn't suffered. In fact you seem to only need it about every ten years.
Thanks for allowing me to come out of the closet.
My name is Cal and I use WD40.
Warning: This cleaning is done by professionals on a closed course. Do not attempt this at home. Actually I have no idea how bad it is but I have many, years old gear that hasn't suffered. In fact you seem to only need it about every ten years.
Hi Cal,
WD-40 can be an excellent switch cleaner. But, all power carrying contacts should be totally clean, no residue. That goes for speaker relay contacts too. The "cleaner" will burn in an arc and make things worse.
Then there is "that smell". In controls you do not want to wash out the lubricant. Clean the metal wiper only. The carbon track is not the cause of the noise.
I use both De-Ox-Id and DeOxid. Both work well. Use as little as you can.
-Chris
Poobah,
Tuner cleaner? Sigh.
WD-40 can be an excellent switch cleaner. But, all power carrying contacts should be totally clean, no residue. That goes for speaker relay contacts too. The "cleaner" will burn in an arc and make things worse.
Then there is "that smell". In controls you do not want to wash out the lubricant. Clean the metal wiper only. The carbon track is not the cause of the noise.
I use both De-Ox-Id and DeOxid. Both work well. Use as little as you can.
-Chris
Poobah,
Tuner cleaner? Sigh.
The wd-40 did the trick, but testlab got me concerned enough
to go back over the stuff that wandered onto the board with
my tuner cleaner and minivac.
But gee, the fun never stops! Now my tuner lamp won't work.
Coinciental? I'll have to go back in and check the leads and see if it
is the lamp. On this receiver the lamp does not function in the aux or phono settings of (guess what) the selector switch. Too much coincidence. Perhaps I'll just leave it burned out.
to go back over the stuff that wandered onto the board with
my tuner cleaner and minivac.
But gee, the fun never stops! Now my tuner lamp won't work.
Coinciental? I'll have to go back in and check the leads and see if it
is the lamp. On this receiver the lamp does not function in the aux or phono settings of (guess what) the selector switch. Too much coincidence. Perhaps I'll just leave it burned out.
Hey Bluebeard,
Another thing that will remove oils, AND carry them away is "brake cleaner"... get it at the auto parts store.... $3. Chlorinated hydrocarbon... it should say "chloro" somewhere in the ingredients. Don't freak out on me here... this is also known "dry cleaning" fluid (you will reckognize the smell right off). Easy on plastics.
We quit buying the $14 electronic stuff when we started reading labels...
Now this won't remove oxides... just guck.
Another thing that will remove oils, AND carry them away is "brake cleaner"... get it at the auto parts store.... $3. Chlorinated hydrocarbon... it should say "chloro" somewhere in the ingredients. Don't freak out on me here... this is also known "dry cleaning" fluid (you will reckognize the smell right off). Easy on plastics.
We quit buying the $14 electronic stuff when we started reading labels...
Now this won't remove oxides... just guck.
I did look at brake cleaner on the shelf yesterday but the ingredients scared the crap out of me. Acetone, ketone, xylene, etc, etc. Nothing was really that dirty. Fortunately I'm pretty careful around the insides of electronics so I used very little of the wd-40. Another nice thing is that this is a late seventies amp and all the components are pretty well spread out on the boards. There just isn't much in the very near vicinity of the switch, so I was able to mop up any overspray pretty completely.
Next time I'll just get a can of deoxit. It's just so damn expensive off the shelf around here. Pennywise and...
Live and learn.
Must be getting late. I hate trite expressions
Next time I'll just get a can of deoxit. It's just so damn expensive off the shelf around here. Pennywise and...
Live and learn.
Must be getting late. I hate trite expressions
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