Hi All
Does anyone know why so many of the micronta 22-203 series voms all suffer the same damage character characteristics? Smoking one particular resistor on the pc board. I am puzzled by this and I am a ham operator of 50 + years w3kfq
Bobby

Which resistor? R15?

It's probably from putting the VOM across 117 VAC when it is set for ohms.

That's exactly what happened to a Micronta 22-203 I owned back in the mid 80's. I took it in to the office one day to check something. This "kid" (I could call him a kid) sees it laying on my desk, says, "Cool!", grabs it and sticks the probes into a wall outlet.

Unfortunately, it was set to "ohms" at the time. The thing goes "POP" and a puff of smoke came out of it! I was pissed!

Exactly what stevebyan said- I think we all experienced this with those R/S meters at least once. That resistor ends up acting as a "fuse" when high enough voltages are applied to the meter accidentally when in a resistance range.

-Mark-