Watts wrong?

[Anthony Guy]

I used to install car stereos & electronics. I had several multimeters, some name-brand and others unknown. The feature most often used was the continuity tester. I no longer work in that field, and the meters have been in a box for many years. When I put fresh batteries in them, none of the tones for continuity were audible. I can understand it happening to one or two, but none of them work. Is this a common thing? What can I do to revive them?

 

[Alec_t]

Had batteries been left in the meters all those years?

 

[Anthony Guy]

No

 

[danadak]

If you meter has a main rotary function switch its not uncommon, over years
of sitting on bench, the contacts get oxidized/corroded a little. Clean that
and see if that helps. Contact cleaner helps, if you dont have that pharmacy
90% alcohol works OK.


Regards, Dana.

 

[Anthony Guy]

If you meter has a main rotary function switch its not uncommon, over years
of sitting on bench, the contacts get oxidized/corroded a little. Clean that
and see if that helps. Contact cleaner helps, if you dont have that pharmacy
90% alcohol works OK.


Regards, Dana.

Thanks, what has me baffled is: the ohmmeter and continuity are on the same position on the dial. The ohmmeter works fine, so there's current getting thru at that point, why would the audio driver be inert?

 

[Martaine2005]

Some meters have springs inside to connect the piezo. It’s not uncommon for those to need a good clean. Others, the wires come loose from taking the backs off for battery and fuse changing.
But all 4 meters of different types?, I’d get your hearing checked no joke, I can hear only two of mine. My children say that all mine are loud.

Martin

 

[Anthony Guy]

I can hear the tones on my Power Probe, so I think the first option makes more sense. Taking the backs off on most of them is pretty involved, it's likely I may have ruined a cold solder connection.

 

[Martaine2005]

Taking the backs off is usually a maximum of four screws.
It’s worth a look inside as it could be very easy to fix.
The rotary switch is another animal. Some have ball bearings that fall out at their earliest opportunity. If in doubt, take lots of photos as you go.

Martin