Fluke 287 problem

[Nevi44]

Evening all.
I have a problem with VDC on my Fluke 287. When measuring 12V DC supply VDC keeps dropping until it stabilizes around 10.85V. After reading many topics on this forum, I am wondering if this can be an issue with MOV’s? They all look intact but two of them (RV2 and RV3) are measuring OL and RV1 19.85 MΩ resistance. Is this correct?

[retiredcaps]

They all look intact but two of them (RV2 and RV3) are measuring OL and RV1 19.85 MΩ resistance. Is this correct?

No.  All should measure 0L.  Desolder RV1, RV2 and RV3 and retest to see if meter works.  Measure RV1, RV2 and RV3 out of circuit to verify readings.

If RV3 still reads 19.85M ohm, replace.  You might also consider replacing RV2 and RV3 as these MOVs are about $1.50 USD each.

[nixxon]

They all look intact but two of them (RV2 and RV3) are measuring OL and RV1 19.85 MΩ resistance. Is this correct?

No.  All should measure 0L.  Desolder RV1, RV2 and RV3 and retest to see if meter works.  Measure RV1, RV2 and RV3 out of circuit to verify readings.

If RV3 still reads 19.85M ohm, replace.  You might also consider replacing RV2 and RV3 as these MOVs are about $1.50 USD each.

To verify if there is a MOV-related problem, would it be sufficient to remove RV1 only. Only RV1 is connected to COM if I have measured correctly...