[Elecraft] [K2] BAND+ push button failure...

[Alan Bloom]

On Sun, 2008-07-13 at 18:26, Don Wilhelm wrote:
> Steve,
> 
> That certainly sounds like you have one of those rare occurrences - a 
> bad switch.  It certainly can happen - actually most any part can fail 
> at times, but a bad switch is quite low on my list of usual suspects.
> 
> 73,
> Don W3FPR

I have a 20-year-old Advantest R4136 microwave spectrum analyzer that I
acquired several years ago in non-working condition.  The sympton was
that every one of the fifty (!) pushbutton switches on the front panel
did not work.  Initially, I was sure it couldn't be that every switch
had gone bad - it had to be a bad interface IC, unseated connector,
malfunctioning microprocessor, etc.

You guessed it - every single one of those 50 switches had indeed
failed.  (Confirmed by the fact that I could toggle each switch function
by bridging each pair of contacts with a clip lead.)  I ended up
disassembling every switch, cleaning the internal contacts with a Q-tip
dipped in alcohol and reassembling.  It took me a couple hours to do all
50 switches.

The instrument works great now.

Al N1AL