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FLUKE 189 DC reading problem [with video]
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windsmurf:
Just some simple things to check on a used meter if it has measurement issues...

Inspect all solder joints
Clean Dial contacts - remove old dielectric grease from the dial contacts with IPA and swab, both sides (board and slider)
Check the PTC, MOV, and input protection resistors
Clean input jack with IPA/swab, check solder for solid electrical connection.  The pin under the jack are sometimes broken.
Check the resistor network for solid contact (both the board and on the resistor itself).  I repaired one that had intermittent connection issues.
windsmurf:
Is your 87V calibrated?  I measure current draw of about 3-5mV less on my 189 than what you get on yours.
Also, 55MOhms at 1000v I think is normal... I get about 48MOhms on mine at 1000V.


I would thoroughly clean your dial contacts on the board as well as the spring contacts under the rotary... and clean the spaces between the dial contact traces.   Not just a rinse with IPA but rub well with a QTip.  Don't lose those springs as they can pop off and fly away...
I might even try swapping the spring contact placements to see if that changes things.

Do you get strange reading with no input/nothing connected to the meter when switching modes?

kamcm:

--- Quote from: windsmurf on August 09, 2019, 07:35:57 pm ---Just some simple things to check on a used meter if it has measurement issues...

Inspect all solder joints
Clean Dial contacts - remove old dielectric grease from the dial contacts with IPA and swab, both sides (board and slider)
Check the PTC, MOV, and input protection resistors
Clean input jack with IPA/swab, check solder for solid electrical connection.  The pin under the jack are sometimes broken.
Check the resistor network for solid contact (both the board and on the resistor itself).  I repaired one that had intermittent connection issues.

--- End quote ---

Thanks a lot. I have checked all of the components you mention. Everything looks good.

I want to check the exact DC voltage go in FLUKE 669918, but I don't know which pin I should probe because no datasheet is available.
It would be helpful if someone can tell me the exact pin of DC voltage go in FLUKE 669918.

Thanks!


CDaniel:
So , just to be sure , there is any range for volt , milivolt , ohm , cap , current that is 100% ok ?
I have a Fluke 187 with ( as far I can see ) identical board so I could check some voltages .
kamcm:

--- Quote from: CDaniel on August 10, 2019, 03:31:38 pm ---So , just to be sure , there is any range for volt , milivolt , ohm , cap , current that is 100% ok ?
I have a Fluke 187 with ( as far I can see ) identical board so I could check some voltages .

--- End quote ---
At the time it behave normally, all the function works well and very accuracy.
But most of the time. The reading just off the spec. 
https://www.eevblog.com/forum/testgear/fluke-189-dc-reading-problem-(with-video)/msg2548869/#msg2548869
The testing was done with fluke 702. I knew My 702 is accuracy and works well, I verify it with a few meters including 289 and 87V 87III etc.

I think the incorrect reading of mA has somethings interesting. In some range the reading just higher than actual.



Actual: 10mA
Measure: 10.072mA  (Get Higher than actual)

Actual: 5mA   
Measure: 5.214mA    (Get Higher than actual)

Actual: 4mA
Measure: 4.062mA   (Get Higher than actual)

Actual 3mA
Measure: 2.763mA (Get Lower than actual)

Actual 2mA
Measure: 0.076mA (Get Lower than actual)

Actual 1mA
Measure: 0.038mA (Get Lower than actual)


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