04-24-2022, 08:08 PM
Its most likely the 2 uF caps in the meter circuit if they are the original molded paper caps and have never been replaced. I would change them before doing anything else.
I have two HP 400D meters and both had upscale readings due to the meter bridge caps. Replacing with film caps cured the problem.
I have two HP 400D meters and both had upscale readings due to the meter bridge caps. Replacing with film caps cured the problem.