[SOLVED]HP/AGILENT/KEYSIGHT 34401A 2W Ohm Problem

[bitseeker]

Yeah, makes you wonder what some of these instruments go through during their lifetime.

[naimns]

I expect the odd S1 wipers reflect the make-before-break and break-before-make in the "Front/Rear Selection Schematic". Drawn out below.
If you are careful, you can remove the switch rod without de-soldering via the Front/Rear opening for inspection. Caution: a high probability of losing the springs.
This 2W/4W fault was another case of a K101 relay fault, not S1 contacts.