three_jeeps

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three_jeeps

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  • 06.08.2017
  • Teardown: Reverse engineering an ultrasonic cleaner
  • To borrow a quote: "Once you eliminate the impossible, whatever remains, no matter how improbable, must be the truth" or in this case, the failed component....I'd bet the transformer is partially shorted. What ever energy entered the power connector was sufficient to take out a 3A fuse and two FETs in series, probably took a parallel route through the transformer (which probably offered less resistance than the semiconductors). I'd replace them (if they can be found). Given the age of the unit, I'd also replace the cap. BTW, you never did say why the Klein DMM ‘burned you.’ Along those lines, wrt the Fluke DMM battery problem you wrestled with, the ‘spring loaded’ connector that transfers power from the battery section to the meter board is, IMHO, a horrid design. I can’t fathom what engineering justification was made to implement that design. Meters take a pounding, more likely when they are billed as ‘industrial’…mechanical connections for something so fundamental is a really bad idea. Good luck.