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I've got a UNI-T UT33D multimeter that's not working like I want it to, and I'm not sure how to find out what's wrong or if it's salvageable or not. The unit is new, but may possibly have had its battery inserted backwards at some point.

I've tried it with two three different batteries, two of which seem healthy when measured by another multimeter, and the third one being new from the store.

Resistance readings I can get are as follows:

  • Setting | open | shorted
  • 200M | OL. | OL.
  • 20M | -0.00 | 1.00 -- battery indication for both
  • 200k | -00.0 | 10.0 -- batt. ind. for both
  • 20k | -0.00 | 1.00 -- batt. ind. for both
  • 2000 | -000 | OL -- batt. ind. for both
  • 200 | OL. | OL. and batt. ind.

There have been times when the shorted readings have been 243, 24.3 and 2.43 instead.

Voltage readings for 20V and 200V DC on a healthy 9V battery are OL and battery indicator.

All of the above readings are taken with black lead in COM and red lead in the fused connection.

I have checked the following:

  • Battery appears healthy
  • Battery is correctly inserted
  • Test leads are not broken
  • Fuses are okay
  • Connection from test leads to inside fuses is okay
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  • \$\begingroup\$ You say the batteries you have tried are ok, but have you checked them with a load? 9V batteries can suffer under loads when depleted of energy, and the internal resistance increases so if it reads for example 8.9V, try sticking a load on and see what the voltage drops to. It could be that the batteries are bad, but the open circuit voltage is fine. \$\endgroup\$ – MCG Aug 22 '18 at 12:38
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    \$\begingroup\$ Also, are you able to take a picture of how your leads are connected (some meters have multiple sockets for the red lead that do different things), and also a picture of you taking a bad reading, vs a good reading from another multimeter \$\endgroup\$ – MCG Aug 22 '18 at 12:40
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    \$\begingroup\$ UT33D you mean? This one? uni-trend.com/productsdetail_1980_1107_1107.html \$\endgroup\$ – Dampmaskin Aug 22 '18 at 12:41
  • \$\begingroup\$ Use a new battery, that way you can rule out the battery. \$\endgroup\$ – laptop2d Aug 22 '18 at 15:08
  • \$\begingroup\$ Are you sure you found all the fuses? \$\endgroup\$ – Spehro Pefhany Aug 22 '18 at 15:31
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enter image description here

You'll need to get a new meter

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  • \$\begingroup\$ How can this have happened? It is literally brand new. \$\endgroup\$ – gibson Aug 22 '18 at 17:53
  • \$\begingroup\$ It's just a cheap meter, the cost for the PCB and components is probably less than 4$ and uses the standard die-on-pcb IC. eevblog.com/forum/testgear/… \$\endgroup\$ – laptop2d Aug 22 '18 at 17:57
  • \$\begingroup\$ And eevblog.com/forum/testgear/… \$\endgroup\$ – laptop2d Aug 22 '18 at 17:57
  • \$\begingroup\$ Manufactures also make mistakes \$\endgroup\$ – laptop2d Aug 22 '18 at 17:59

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