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Electronics => Repair => Topic started by: felixd on October 21, 2015, 12:27:17 am

Title: [Fixed] Polish Unitra AMS-3 DMM
Post by: felixd on October 21, 2015, 12:27:17 am
I've just received not fully working digital multimeter Unitra AMS-3 [Made in Poland] I bought on our local auction portal.

What was wrong?
 * Blown up 2A fuse

That was first thing I've changed. After replacing fuse I've carefully checked current measurements on all ranges. It worked just fine.
Seller stated that device is blowing 2A fuse every time they try to "take measurements". I've no idea what and how they've been testing.

 * Broken connection on higher voltage ranges path.

Resistance measurements were working just fine on all ranges but there was still a problem with higher voltage ranges. After taking apart whole device I found broken connection. After fixing that problem device came back to live again!

Multimeter parameters/ranges:
DC/ACV: 2, 20, 200, 1000
DC/ACmA: 2, 20, 200, 2000
kOhm: 2, 20, 200, 2000

Please find below teardown pictures.


and some videos
Title: Re: [Fixed] Polish Unitra AMS-3 DMM
Post by: crispy_tofu on October 21, 2015, 01:14:35 am
Wow, looks like a fantastic piece of kit. Thanks for sharing!  ;)