I've got a Rat Shack (micronta) 22-174B that I use for my hobby, which is building guitar effect pedals. It's a cheap unit, but it's got the functions that I need, such as a capacitance meter, hfe, etc. Anyhow, I can't get good ohm resistance readings at all anymore. It is way off. And the continuity tester beeps if I hold both a lead in each hand. I put in fresh batteries, the internal fuses are good, etc. Anyone has an idea?
DMM acting flaky
Feb 11, 2006
4 Replies
Not very familar with the RS products, but many DMM's use a ratiometric configuration with the reference resistor in series with the unknown. You may have blown the reference resistor.
Peobably some of its referencing resistors are blown. Maybe someone put aome voltage through the meter while it was in the ohms mode. You will most likely need the service manual for the meter in order to service it. You will also need the parts source for the meter's parts. These resistors are generaly precision resistors. Using regular off the shelf ones would not be accurate.
Jerry G.
Thanks for the reply, I'm trying to find a schematic and parts source for it, wouldn't you know, the Rat Shack is of little help.
Thanks for the reply, I'm trying to find a schematic and parts source for it, wouldn't you know, the Rat Shack is of little help.
Join the Discussion
Have something to add? Share your thoughts — no account required.
Didn't find your answer?
Ask the community — no account required