A number of the switches on the 465 use PC board pads as contacts. They
have heavy gold plating, but eventually the gold wears off. When that
happens, the switch is dead and as far as I know can't be repaired. You
might be able to squeeze a little more life out of it by cleaning, but
in any case I'd be very careful not to use a cleaner with any abrasive
qualities. If cleaning doesn't cure the problem, worn pads might be the
cause.

But by all means check with the 'scope newsgroup. I'm sure you'll find
folks who have had a lot of experience with the 465, and some might even
know of some kind of fix or replacement for worn switch contact pads.

Roy Lewallen, W7EL