Brymen DMM Warranty and mods ??

[lordvader88]

I have a Brymen BM869s and it's working fine, but the continuity buzzer is way too loud for just using in my room. I bought it new from ebay, maybe 2yrs ago. The guy sells a lot of them from Italy. Anyone know if there's any warranty on these from the factory ?

If not, or if it was almost up, I want to drop the volume on this a bit and make the backlight stay on longer. If I can get in there safely. These have 2 PCBs and lots of funny connections I think.

[coromonadalix]

This model use a dedicated chipset,  no specs have been found ..

[lordvader88]

I'd hope that changing a resistor would lower the volume, and changing some capacitor would increase the light delay.

[radiolistener]

Does your DMM shows measurement change when you rubbing display with finger?

[ct1bxt]

Just made the test and no change on mine.
Rodrigo

[radiolistener]

could you try this:
Select Voltage measurement, autorange and keep probes open.
Then slide your finger from left down corner to up.

Does it affect measurement result?

My 867 shows voltage jumps up to 0.03 V.
The same thing happens on R measurement, for 1 MOhm it may show even 0.3 MOhm at the moment of slide.
Is this ok?

I wrote to brymen support some time ago and they told me the following:

normal phenomenon. It is because the test current for 6MOhm range is less than around 0.125uA. For such kind of low current, the measurement may be easily affected by noise. If it gets 1Mohm reading while you do not touch plastic glass, then it should be no problem.

Also, when I slide finger from the left down corner to up, I see liquid crystal flashes on the display.
It seems, like high static electricity is induced on the other side of plastic glass.
May be there is need to use antistatic spray on the back side of the plastic glass?

[indman]

May be there is need to use antistatic spray on the back side of the plastic glass?

It is necessary to paste on the screen only a simple protective transparent film which protect displays of mobile phones.

[gearedbyby]

Connect the resistor to adjust the volume, design a repeatable trigger monostable control backlight

[Gyro]

If it's a PCB mounted sounder (as opposed to a piezo disk glued to the back), then a simple self adhesive label stuck over the hole in the top usually provides about the right amount of sound attenuation.

[ct1bxt]

Hi,

in AC voltage, do the same hear, 0.034 volt.
DC voltage, no change.

Rodrigo

could you try this:
Select Voltage measurement, autorange and keep probes open.
Then slide your finger from left down corner to up.

Does it affect measurement result?

My 867 shows voltage jumps up to 0.03 V.
The same thing happens on R measurement, for 1 MOhm it may show even 0.3 MOhm at the moment of slide.
Is this ok?

I wrote to brymen support some time ago and they told me the following:

normal phenomenon. It is because the test current for 6MOhm range is less than around 0.125uA. For such kind of low current, the measurement may be easily affected by noise. If it gets 1Mohm reading while you do not touch plastic glass, then it should be no problem.

Also, when I slide finger from the left down corner to up, I see liquid crystal flashes on the display.
It seems, like high static electricity is induced on the other side of plastic glass.
May be there is need to use antistatic spray on the back side of the plastic glass?