Uni-T UT71A - capacity

[Horus92]

Hello!

I'm newby on the forum. I asked already in german forums, but I found so far no solution for my problem.

I have bought a multimeter UT71A UniT on Ebay (Condition: new).

Now I have found with the first measurements of the capacity that this does not function (it shows only 0.00000 F). I have of course taken the polarity of electrolytic capacitors.
The capacitors are new (400V, 3.3 uF). I wait a long time, but nothing measurement. Also other capacitors were not working.
The batteries of the multimeter are replaced.

I opened the multimeter gently and i see  a black wires with one end loose. In pictures from
the board on the web, it does not exists.

What is the purpose of the wire? Where is one ran the loose end.

Does anyone have a similar mistake on his multimeter once before. Why can I not measure capacity?

Can someone help me?

Best regards, Horus92!

[Horus92]

I found out that the Voltcraft 940 is the same as the UT71. In the appendix is ??the circuit diagram.

Which part of the circuit is for capacity measurement? What should I consider?

[Wytnucls]

I think your IC is the Cyrustek ES51922.
If that is the case, check components and traces to pins 46, 47, 48 and 49.

http://www.cyrustek.com.tw/product-1.htm

[Monkeh]

Your meter is faulty, you bought it new. Get a refund.

[retiredcaps]

What is the purpose of the wire? Where is one ran the loose end.

Usually these bodge wires are found on CEM Instruments meters.  Uni-T meters do have bodges in the form of stacked SMDcomponents, but I haven't seen one with a wire especially one that goes nowhere.  It is like someone used the bodge wire to fix something, but didn't do a very good job of soldering and shipping/handling caused the package to be moved and the wire to fall off?

If you bought it new, I agree you should return it.  Hopefully, shipping costs won't exceed the cost of the meter.

[Horus92]

I found with the continuity tester, that the wire is connect the emitter from Q4 with the resistance R22. The Resistance is connect with Pin18 (OHV).

The emitter from Q3 is the GND.

I think it is vice versa on the circuit diagram.

[WackyGerman]

I see a spot next to Q4 and the bodge wire ? Is that solder ? Then it shorts two traces . You should remove that

[carl_lab]

Gib den Murks zurück...