Cleaning old oscilloscope rotatory switches

[Belrmar]

Well i got an old promax od-416, it had some faults but most of them are fixed . now i am vaving some problems with the rotatory switches . sometimes they dont make a correct contact and the offset and time constant goes crazy, turning the switch a few times fixes it, but not as ideal as i would like it to be

[Harb]

Deoxit.......works a treat, spray it on the contacts and twist the knob a few time and 9 out of imes its fixed

[rhb]

Much safer to soak a piece of bond paper in Deoxit and pull that through the switch contacts.. 

Do NOT spray cleaner around the input attenuator section unless your intent is to destroy the scope.  Tek warns about this in their service manuals for the 465 et al.  It's apparently  very bad for the capacitors.