Fluke 8060A DMM DC Parasitic Leakage Current

[RF-Engineer]

The Fluke 8060A is my all-time favorite DMM.  Among several reasons, I like to manually range my DMMs without having them hunt to an appropriate range.

Over the last few years, 9V battery replacement has been needed way too often.  The 8060A can be sitting on the shelf in the off position for weeks at a time but when I grab it for measurement, it nearly always shows a low battery voltage indication.  My thought was that a parasitic leakage current was occurring somewhere to prematurely drain the battery.   

In reviewing the schematic, only one component is always across the battery and it's a 0.01uF 50V X7R ceramic disc cap.  The cap is used to assist with transient reduction when a DC wall-cube is used for DMM powering.  I never use a wall cube with my 8060A so I extracted the cap and didn't replace it.  Given the age of the 8060A, the cap was likely manufactured in the late 1980s.  But so far, so good: a new battery has lasted for several months.

White papers describing capacitor insulation resistance make it seem like small X7R cap sizes should have a near infinite DC resistance, even with aging.  So, is it likely that it's a bad component from the initial manufacturing processes, or something age related? 

Paul

[daisizhou]

I am also using fluke 8060a which ceramic capacitor are you referring to? Are there any pictures?

[Kleinstein]

MLCC, especially the SMD versions are somewhat susceptible to mechanical damage, e.g. from flexing the board. With a mechanical crack there can than be additional leakage or even a short.
The THT parts are usually quite reliable, inless really stressed.

[RF-Engineer]

I am also using fluke 8060a which ceramic capacitor are you referring to? Are there any pictures?

It's C37, located on the PCB near the 9V battery compartment.

Paul