Author Topic: Faulty multimeter recycling  (Read 351 times)

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Offline rodolfok

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Faulty multimeter recycling
« on: December 06, 2017, 03:44:19 AM »
Hello,
I have a digital multimeter of an Italian brand, Nimex NI2100, that was working ok until it suddenly gave erroneous readings, like 140V/AC instead of 220V/AC. I most pobably did something wrong that damaged it, because I can recall that I changed a blown fuse (200mA) with one I had as spare, but improperly of a higher current rating.
I would like to know if there is some troubleshooting that can be done to possibly try a repair, to find out which could be the broken part, or if it's not worth the time. In the latter case, would there be some part of it to recycle, like e.g. the display, or just use the DC voltage measurement, maybe attempting a calibration.
regards
rodolfok
 

Offline Kleinstein

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Re: Faulty multimeter recycling
« Reply #1 on: December 06, 2017, 04:08:51 AM »
With handheld meters a repair can be rather difficult. One problem is that the calibration procedures are often nor known and a professional calibration might cost more than many handheld meters.

There are a few chances if the damage is visible (e.g. blown fuse / PTC ...) and not a critical part that effects the calibration.

With handheld DMMs there are not that many parts worth to recycle: maybe the shunts. Using as DC only or Voltage only might be an option.
 
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Offline james_s

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Re: Faulty multimeter recycling
« Reply #2 on: December 06, 2017, 07:21:00 AM »
Try poking around in the front end circuits, look for resistors that have gone open or changed in value, MOVs that have been damaged by surges and such. Also check the range selection switch for damaged or oxidized contacts. Otherwise it's pretty hard to offer much specific advice unless a schematic is available.
 

Offline CJay

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Re: Faulty multimeter recycling
« Reply #3 on: December 06, 2017, 08:25:56 AM »
Check the battery.
2E0EOA
 

Offline retiredcaps

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Re: Faulty multimeter recycling
« Reply #4 on: December 06, 2017, 08:49:54 AM »
If it is this meter shown, any number of generic 830 multimeter schematics will give you a close approximation.

This meter is sold under various brands.
 

Offline rodolfok

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Re: Faulty multimeter recycling
« Reply #5 on: December 06, 2017, 06:39:41 PM »
If it is this meter shown, any number of generic 830 multimeter schematics will give you a close approximation.
Yes, mine it's a previous version because I only have 200uA.
thanks
 


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