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Electronics => Repair => Topic started by: rolkinas on January 09, 2017, 12:35:47 am

Title: UT804 repair/schematics
Post by: rolkinas on January 09, 2017, 12:35:47 am
Hi everyone!

Does anyone have schematics of UT804 or UT71D multimeter?

Mine ut804 stopped measuring ac voltage. Some time ago it started hanging when touching mains voltage with Com probe. It doesn't matter if meter was powered by mains or batteries.
Other measurement seems to work. Still.
Title: Re: UT804 repair/schematics
Post by: JFJ on January 09, 2017, 12:50:36 pm
The attached pdf file is a schematic for a Voltcraft VC940 multimeter - possibly a re-badged Uni-Trend UT71D?
(https://www.eevblog.com/forum/repair/ut804-repairschematics/?action=dlattach;attach=284124)
Title: Re: UT804 repair/schematics
Post by: rolkinas on January 09, 2017, 08:12:37 pm
Many thanks for schematics!
Voltcraft is quite similar to ut804. Fault was in power supply not delivering positive voltage to ES636. Now it works as usual slowly, but works (: