BM869S not reading correct voltage

[radiolistener]

"Segments flashing" I have no idea what that looks like, is that the bar graph?

No, mostly 7-segment element at the bottom left corner of transparent display window, where this issue can be reproduced.
The segment flashing with high contrast black color and then smoothly fading off.

But I notice this issue with LCD flashing was more high when DMM was new, just out of the box.
Later, when display plastic is contaminated with dust, it going to almost not noticeable, but still present...

I think there is some kind of flaw DMM design, coincidence of the case design, the properties of the case material and insufficient shielding of the electronics. It leads to some induction of static electricity on the inner side of plastic window and as result it leads to some electrostatic effects on LCD and measurement part.

I think the plastic transparent window of DMM works like capactior, where outer surface is one capactor terminal and inner window surface works like second terminal of capacitor. It allows to induce high electric charge on inner window surface by touching outer window surface. Or something like that.

[LDDM]

Small update, i've contacted Brymen via the email mentioned previously, and still waiting for a reply.
I'm a bit disappointed by Brymen multimeters and how a DMM can fail like that.

Regarding the test leads, i have tested other leads i have and got the same result in my test so the brymen leads are not at fault here. Moreover they have not been stretch or anything else. 
I bought a new multimeter and will try do diagnose my two BM869s when i receive it. It would be nice to have a Schematics but could not find one online.

[sonpul]

I once encountered a Brumen multimeter that did not measure AC correctly. I only recently remembered this experience. I came to the conclusion that this behavior is due to the failure of the AD737 True RMS converter. The model was BM521. If I'm not mistaken, in the case of BM869s the AD636 converter is used.

[J-R]

Maybe this is a flash memory issue and some calibration points were lost.  Once you get another DMM and start poking around, you could try calibrating a specific function/range to see if it makes any difference.

Ian is looking for faulty test gear.
Although if any BTC IC is faulty, he may not be able to repair it.
 


Could sell them for parts.  If someone has blown a hole in their PCB or cracked the display for example.

[Fungus]

Maybe this is a flash memory issue and some calibration points were lost.

On two meters simultaneously?

[joeqsmith]

Maybe this is a flash memory issue and some calibration points were lost.

On two meters simultaneously?

Possible, once details about the alignment were made public, it does seem the kiddies like to try and run through them using what ever they have laying around as a standard.  And we have  seen people who feel they need to have two meters reading identical to the last place.   

[J-R]

The BM869s and other Brymen DMMs obviously have a small amount of flash of some kind for the calibration data as well as the mode memory. If there was a manufacturing defect of some sort the data stored there could degrade over time.