How to clean a push switch? Hafler DH 110

Archived from groups: rec.audio.tech (More info?)

Hello,

I've had some success by removing the plastic knob and dripping the
cleaner down the shaft, working the button in and out as you do it.
Sometimes it helps to stand the preamp so that the front panel is facing
the ceiling, so the fluid can be helped by gravity. Some switches have
a plastic collar just behind the knob, so you have to remove the panel
(or the switch) to get to where the shaft enters the body of the switch.

Regards,
Tim Schwartz
Bristol Electronics


labornot@yahoo.com wrote:
>
> I just purchased a Hafler 110 preamp. I powered the preamp, no blown
> breakers, sparks or burning insulation :-) I dropped it into my system
> to put it through its paces and all seemed well until I started pushing
> the four push button contols; mono, filter, tone and epl. When I pushed
> the "filter" button the volume of the right channel dropped 80%.
> Cycling that button produced a few crackles, but no improvement. I
> understand that this a common problem with Hafler push buttons. Does
> anyone have experience opening the plastic switch box for chemical
> cleaning? I'd like to squirt some Deoxit inside, but dread breaking a
> switch. I've thought of using a hot needle to melt a hole and putting
> the aerosol needle in that. If worse comes to worse, are there
> replacement switches available?