I have a hobbico digital voltmeter and it is about 8 yrs old never dropped or mishandled. When I go to check out my rx batteries the volt readings go up and down as in malfunctioning . I changed the 9 volt battery and still has the same thing . if I switch it on and off and get it to read steady 0 v then I get a solid reading . Do they wear out over time there's very little that can wear out . could my switch be bad ???? Please advise and thank you in advance for all your help ...
Ken