This had two major faults, the NiCd battery had failed and leaked and the power switch is very reluctant to switch on without a lot of alarming arcing.
I quickly removed VARTA, destroyer of worlds, replaced with two NiMH AA cells in a holder, though I might change this to AAA when I get a replacement battery holder. The PCB needed some cleaning but the leakage wasn't as bad as I've seen in other equipment. I changed C21, a 560pF capacitor and adjusted the parallel trimmer to accommodate the slightly different value of my replacement part.
I've left the switch for now but I need to remember not to turn it off, too.
I fed it a pile of resistors, then some outputs from my bench supply and HP 3325A+HV option, measured using the HP 3456A for reference. I didn't succeed in the current calibration, it kept saying BAD, but it wasn't far off, everything else worked.
It's not a bad meter but the AC ranges take several seconds to settle and that's a bit annoying. I think it's doing software averaging. I really like the big LED display and assuming it's reliable it might even become my daily driver on the bench (the Fluke 45 is becoming cantankerous and its VFD is fading).
Another bad point is disassembly, which was horrible due to having to remove hard-to reach plastic and metal nuts, but I'll forgive it that if it continues to work for a few weeks.
I gotta find some decent TE to work on. Been very lean here lately.