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Old 11th May 2019, 11:21 pm   #1
Phil G4SPZ
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Join Date: Apr 2005
Location: Bewdley, Worcestershire, UK.
Posts: 4,748
Default Avo EA113 faulty resistance range fixed - again

Almost exactly two years ago, I posted this Success Story and since then the instrument has given excellent service as my main workshop meter.

This week, a fault appeared, namely the loss of the 'ohms x 100' range. I studied the circuit diagram and homed in on R59 (10k) which on inspection had a very obvious dry joint at one end, shown by the white arrow in the attached picture. I re-soldered the joint and all was well again, but a little bell rang somewhere in the deep recesses of my memory that I had done this before. Sure enough, I had re-made this same joint exactly two years ago, and I mentioned it in the original posting.

I can't explain why this joint has failed again. I'm not known for making dry joints. Perhaps there is some residual contamination present which led to the joint failing? I will put a note in my diary to open the meter up in May 2021 and check it again!

Phil
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