Date   : Fri, 17 Oct 2008 07:49:56 -0500
From   : jules.richardson99@... (Jules Richardson)
Subject: master keyboard

Mike Tomlinson wrote:
>> Shouldn't it be possible to pull
>> them apart and clean those keyswitches,
> 
> If you mean taking the keyswitches themselves apart, no.

Hmm, I have a feeling (without any handy to check) that they do come apart - 
but the casing is all clipped tightly together; you need to desolder the 
switch from the PCB and then use a very fine flat-blade jeweller's screwdriver 
to coax the halves apart. Time-consuming and tedious - save that job for 50 
years' time when there's no donor parts available any longer :-)

>> or is it not a failsafe way
>> to make them work again?
> 
> _sometimes_ a squirt of contact cleaner (e.g. rswww.com part number
> 132-491) in between the white plunger and black switch body, followed by
> a good dew operations of the switch, works. Usually though, the switch
> is plain worn out.

Yeah, I think the sprung components tend to bend a little over time, so the 
contact's not as strong as when new. They could probably be bent back, but it 
might be tricky to do that and retain the correct 'feel'.  Plus it's hard to 
judge how long such a fix might last (hmm, little motor-and-cam switch tester 
maybe -  give it 500 presses and make sure that all 500 work? :-)

cheers

Jules