Quote:
Originally Posted by Barnmead
...look at R11 which should be 450 ohms...
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I agree with Richard's diagnosis. Avometers are nothing if not logical. The 10V AC range has a separate multiplier (series resistor) of 470 ohms, which feeds a tapping on the current transformer, but all the other AC voltage ranges and all the DC voltage ranges share the common multiplier chain. Hence the combination of symptoms you report points strongly to R11 being open-circuit.
A standard resistor will do; select one from a batch of 470 ohm 10% components using a DMM and fit the nearest to 450 ohms that you can find. It can be bridged across the faulty bobbin. Hopefully, you'll find that all the voltage ranges start working again.
Avo rotary switches, in my experience, are very rarely at fault. The leaf switches, on the other hand, will almost always require cleaning in the way The Philpott has suggested.
Good luck!