I looked inside my dso to find a bad solder cause i had erratics values sometimes
Testing the voltages and after re soldering some resistors, i finaly decided to test the sensels voltages in all the scale of V/div as suggested
During this test i accidentally (^^) touch 2 pins with the probe and eared a quick short
it was very soft but enough for making some lack in v/div scale by the way
so...i found the microcontroller at "RS-particuliers" in France with a 24h delivery and did the job (near 6 euros the piece) It would be less expensive in CHINA but 3 weeks...it's a choice...
So to do that better to have, microscope, Flux and paste for CMS, and good soldering tools, hot air gun if possible.
Then you need to charge new firmware, as usual
be carreful if you want to test with probe so
Repair is done and everything is ok in 24H
to share with you
Best regards Eric.
