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These three images I took from an eBay ad for the service manual, but I lost out on the bid and not sure who has it now. People should just scan and post this stuff.
I have the Tech 360 manual scanned w/schematic but did not find a way to make it a multipage PDF. I think the 350 verses 360 schematic label is swapped in the manual. I forgot, it's been a while since I was into these. They are a great multimeter for doing service, the 20Ω range has 4mA test current which is unique.
I have some parts like that knob and Allen-Bradley potentiometer 3000-090-108? 5MEG? and the plastic mount. Would trade for a LCD front bezel.
I'm in the stupid Beckman multimeter LCD rot and zebra strip drama, it's the main weakness with these, as I have a few to repair. Made in USA baby.