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mole42uk · 23rd Sep 2018, 5:01 pm

I'm rather sad to report that I've damaged my Keithley 175 DMM by testing a voltage that I thought was 270V only to find that it was nearly 2kV.

The meter passes the self-tests but when switched to measure DC voltage and the input shorted the display shows a cycle of several different voltages and sometimes the over-range indication. Selecting the Ω range gives similar nonsense.

Visual inspection of the PCB does not reveal any damaged component or fuse.

Has anyone experience of this DMM and can suggest a possible line of diagnosis? I do have the official service manual.

23rd Sep 2018, 5:01 pm	#1
mole42uk Nonode Join Date: Aug 2010 Location: Resolven, Wales; and Bristol, England Posts: 2,608	I've injured my Keithley 175 DMM I'm rather sad to report that I've damaged my Keithley 175 DMM by testing a voltage that I thought was 270V only to find that it was nearly 2kV. The meter passes the self-tests but when switched to measure DC voltage and the input shorted the display shows a cycle of several different voltages and sometimes the over-range indication. Selecting the Ω range gives similar nonsense. Visual inspection of the PCB does not reveal any damaged component or fuse. Has anyone experience of this DMM and can suggest a possible line of diagnosis? I do have the official service manual. __________________ Richard Index: recursive loop: see recursive loop