Attenuator switch noise

[Karl5150]

As documented in several posts I have a Mourquiet in my SII and shameless copies in both my S.E.X. amps. That's a total of 6 of the very nice Switchcraft switches, 5 of which have always worked flawlessly.
The sixth started giving me scratching/popping about 3 months after installing it. It is in the course position and only makes noise when actually switching. The first time I cleaned the contacts with swabs and Caig spray cleaner. It was quiet for 6 months or so but then the switching noise returned.
I know BH has supplied many of these switches and I am wondering if anyone else has run into this problem. Any information on where I should be concentrating my efforts would be greatly appreciated.
TIA,
Karl 

[Deke609]

Karl - I had a similar issue with a Mourquiet course attenuator. I would get a brief static/popping sound when switching to/from the 4th position.  After numerous unsuccessful attempts to find something wrong with the switching mechanism (stray solder or flux, bent contact, etc.), I finally discovered that it was an unsoldered connection.  The joint was very well crimped, so functioned fine when in the 4th switch position, but the strong vibration from moving to/from the position would momentarily jostle the connection producing the static/pop. No problems after soldering the joint.

cheers, Derek

[Tom-s]

Do show us your implementation of the switches in your S3X! 

[Karl5150]

Thanks for weighing in Derek, since it pops at every step I'll look more carefully at the in and out hook-ups of the switch.

Tom-s - There are a couple of photos and description in two posts, currently on page 3 of the S.E.X. Kit forum: Titled SEX3.0.1 and SEX2.1.1, they were both started by me.

Karl

[Karl5150]

After putting up with the loud pop again whenever I used the coarse switch I took the amp home and re-flowed all the in and out joints, to no avail. (The fact that was is in both channels and all positions made me think that unless it was the ground lead it wasn't a soldering issue, but I wanted to cover the bases.)
I again sprayed and swabbed the switch contacts, above and below the deck = Dirty, oily looking swabs and silent switching.
As I posted earlier, a total of 6 switches in 3 amps, all installed by me and this is the only one that has given me any problem. The thought of replacing the pricey switch (if available) is not appealing so again any insight would be appreciated. Paul(s)? Doc?
Thanks,
Karl 

[Doc B.]

Dirty - noisy. Clean - quiet. Seems like you have solved the issue yourself. Why one switch only? Dunno, maybe it was a little more oxidized to begin with. I'd suggest a regular maintenance schedule as the best solution without replacing the switch. When you do it also clean all your other connections - interconnects, power cords, etc. If that switch is in an environment where it oxidizes in three months it's safe to assume the other contacts in the system are being affected as well.

[Paul Birkeland]

The switches use silver contacts, so periodic cleaning is probably a good idea.

[Karl5150]

Thanks guys, I guess I can use it as a reminder for all the other housekeeping duties.