EEVblog 121GW Multimeter Issues

[Seppy]

Same experience with emails.

BTW, has anyone tried Low Z measurements? Can somebody check for me if it works for voltages below, say, 5V? It doesn't work for me even on latest firmware (but I think I destroyed calibration data, so can be my bad if it's fixed). It would be great to have a list of bugs somewhere to see what's fixed and what is not.

Low Z is not designed for low voltages. It is designed to eliminate ghost voltages (usually on higher voltage AC lines).
It is not expected that this range work below around 12V.

[exe]

Low Z is not designed for low voltages. It is designed to eliminate ghost voltages (usually on higher voltage AC lines).
It is not expected that this range work below around 12V.

Got it. May it's worth mentioning in the docs for noobs like me. BTW, why is it only for high voltages? For me it would be useful for low ranges as well.

[Welectron]

I have still not received the shim.

I emailed dave, david and susan multiple times about this, yet never got a reply back.

I'm pretty disappointed how this is being handled by dave..

Please leave us a PM, we will take care of it.

[Seppy]

Another point I found was when I was doing the overnight SD card data logging.
one of the file had garbled data in the file, when I was testing for the thread in the forum.

https://www.eevblog.com/forum/testgear/new-eevblog-branded-multimeter-coming/msg1398530/#msg1398530

The data is corrupted as bellow in the middle of the data.
59625,DCV,049.997,V,,,,,,,,
59626,DCV,049.997,V,,,,,,,,
59627,DCV,049.996,V,,,,,,,,
59628,DCV,049.997,V,,,,,,,,
59629,DCV,                                                                                                                                                                                        59641,DCV,050.001,V,,,,,,,,
59642,DCV,049.996,V,,,,,,,,
59643,DCV,049.996,V,,,,,,,,
59644,DCV,049.998,V,,,,,,,,
59645,DCV,049.996,V,,,,,,,,

The garbled line only happened in one line out of four files of data logging.
The other three files had no issue.

The firmware is 0.01 and the SD card is the SunDisk which is included in the meter as a factory default.

I attached the original file with zip compression to work around the file size limitation on the forum.

Hope these report help improving the meter.

Thanks for the report, good to know.
Can you upgrade your multimeter firmware to the latest then see if the error still occurs, we didn't attempt to deal with that issue some time back with a firmware upgrade.

[darik]

My meter has been working great, but I have noticed another cosmetic issue I think is worth mentioning.

I find the red ink for the alternate modes on the labels around the selector knob really hard to read in anything but fairly bright lighting. If you're going to produce any more I think it would be a big improvement to find a hue that pops better off the charcoal.

[galleno64]

Hello.  I'm backer #1063.  I got my 121GW meter today and was super excited.  That is until I tried to turn it on, and nothing happened...  I've checked the factory installed batteries and they're fine.  Can any one help me either get this one fixed or tell me if there's a reset button I could try?

Thanks

[comeau]

Got my meter today. Worked great first time I turned it on. Then I went to monkey with it later and found that the date and time wouldn't save no matter what I did. Anyways I kept messing with the settings and next thing I know nothing works. The light started turning on and off and it switched from AC/DC reading. I think it must be the mode button. This makes sense because when I turn it on it starts the cal process and displays "Cal.1" . I took it apart to try to take a look but nothing obvious is wrong. Tried updating the firmware, no luck.

Anybody else having these issues?

Where do I go to actually report this so I can get a replacement?

Edit: After looking at some pictures I took, it seems the pull-up resistor R3 is not populated. (I'm guess the X in the diagram means do not populate so thats fine) That means they're doing the pull-up on the STM32. Any chance this may be the cause of my issues? Issue is frustratingly intermittent. Firmware U-1.22

[1anX]

That black plastic molding for the switch is either cracked or malformed. I would ask for a replacement part for it, but I'm guessing they will replace the meter with one that works.
I really thought the quality of this UEI manufactured meter would be better than this! Having said that, my meter works fine and I'm loving it.

[comeau]

That black plastic molding for the switch is either cracked or malformed. I would ask for a replacement part for it, but I'm guessing they will replace the meter with one that works.
I really thought the quality of this UEI manufactured meter would be better than this! Having said that, my meter works fine and I'm loving it.

Are you talking about the rotary switch? It is perfectly fine, it may look worse because of the lighting.

[JonM]

Dave or David - It would be good to have a version or date for the manual on the 121gw page. Today I got the Kickstarter reminder on firmware (I already had 1.22) and manual updates. I tried to download the manual to see if it is newer than the 24 May version I have. The download was very slow (5+ minutes) so I just canceled.

Maybe the Kickstarter reminder caused a server overload? (Mostly joking about that).

In any case, if the manual version was listed I might not have needed to attempt the download.
 

[Seppy]

Dave or David - It would be good to have a version or date for the manual on the 121gw page. Today I got the Kickstarter reminder on firmware (I already had 1.22) and manual updates. I tried to download the manual to see if it is newer than the 24 May version I have. The download was very slow (5+ minutes) so I just canceled.

Maybe the Kickstarter reminder caused a server overload? (Mostly joking about that).

In any case, if the manual version was listed I might not have needed to attempt the download.

Good idea, I'll add it now.

Edit : Added, your manual is out of date.

[Seppy]

Got my meter today. Worked great first time I turned it on. Then I went to monkey with it later and found that the date and time wouldn't save no matter what I did. Anyways I kept messing with the settings and next thing I know nothing works. The light started turning on and off and it switched from AC/DC reading. I think it must be the mode button. This makes sense because when I turn it on it starts the cal process and displays "Cal.1" . I took it apart to try to take a look but nothing obvious is wrong. Tried updating the firmware, no luck.

Anybody else having these issues?

Where do I go to actually report this so I can get a replacement?

Edit: After looking at some pictures I took, it seems the pull-up resistor R3 is not populated. (I'm guess the X in the diagram means do not populate so thats fine) That means they're doing the pull-up on the STM32. Any chance this may be the cause of my issues? Issue is frustratingly intermittent. Firmware U-1.22

The solder mask, center left is damaged, this is a manufacturing defect, this unit needs to be replaced.
Please PM me your backer details, email address for correspondence and address (if it changed).

[wraper]

The solder mask, center left is damaged, this is a manufacturing defect, this unit needs to be replaced.
Please PM me your backer details, email address for correspondence and address (if it changed).

I don't see any solder resist damage  . However C23 is soldered on footprint of larger size and looks like tombstoned. Although it might be just lighting.

[ChunkyPastaSauce]

The solder mask, center left is damaged, this is a manufacturing defect, this unit needs to be replaced.
Please PM me your backer details, email address for correspondence and address (if it changed).

I don't see any solder resist damage  . However C23 is soldered on footprint of larger size and looks like tombstoned. Although it might be just lighting.

Circled areas:  https://imgur.com/a/dAZVSSC

[wraper]

The solder mask, center left is damaged, this is a manufacturing defect, this unit needs to be replaced.
Please PM me your backer details, email address for correspondence and address (if it changed).

I don't see any solder resist damage  . However C23 is soldered on footprint of larger size and looks like tombstoned. Although it might be just lighting.

Circled areas:  https://imgur.com/a/dAZVSSC

That's light reflection, not damaged solder resist.

[Seppy]

Hello.  I'm backer #1063.  I got my 121GW meter today and was super excited.  That is until I tried to turn it on, and nothing happened...  I've checked the factory installed batteries and they're fine.  Can any one help me either get this one fixed or tell me if there's a reset button I could try?

Thanks

Hello.  I'm backer #1063.  I got my 121GW meter today and was super excited.  That is until I tried to turn it on, and nothing happened...  I've checked the factory installed batteries and they're fine.  Can any one help me either get this one fixed or tell me if there's a reset button I could try?

Thanks

Hello, are you able to open up the meter and take photos similar to comeau? A replacement unit is on the table but it may be something simple, would be faster to fix it.
I would attempt to remove the plastic rotary switch and make sure that the contacts are seated correctly, a photo would be very helpful

[Seppy]

The solder mask, center left is damaged, this is a manufacturing defect, this unit needs to be replaced.
Please PM me your backer details, email address for correspondence and address (if it changed).

I don't see any solder resist damage  . However C23 is soldered on footprint of larger size and looks like tombstoned. Although it might be just lighting.

Circled areas:  https://imgur.com/a/dAZVSSC

That's light reflection, not damaged solder resist.

I think we should reserve that judgment to comeau, he will have a definitive answer to that.

[comeau]

I think we should reserve that judgment to comeau, he will have a definitive answer to that.

Can confirm solder mask appears intact, just the lighting. Sorry, it is difficult to get good lighting.

I don't see any solder resist damage  . However C23 is soldered on footprint of larger size and looks like tombstoned. Although it might be just lighting.

C23 doesn't look pretty, but it appears to be in good contact.

[bicycleguy]

Dave or David - It would be good to have a version or date for the manual on the 121gw page. Today I got the Kickstarter reminder on firmware (I already had 1.22) and manual updates. I tried to download the manual to see if it is newer than the 24 May version I have. The download was very slow (5+ minutes) so I just canceled.

Maybe the Kickstarter reminder caused a server overload? (Mostly joking about that).

In any case, if the manual version was listed I might not have needed to attempt the download.

Good idea, I'll add it now.

Edit : Added, your manual is out of date.

FYI the July 9 Manual link provides a Manual with 25 June on the front page.

[bicycleguy]

Haven't seen quite this issue posted.  Appears the auto range doesn't work when the meter's batterys are at ~5.2V and try to measure something around 6V.  It is supposed to work with the batteries as low as 4.2

https://youtu.be/CXcKBs3Twv8

Worked ok with the measured batteries in the meter.  Will try some more experiments with different voltages.
Edit: I probably switched range from AUTO DC to AUTO DC+AC.  See further posts next page.

[Seppy]

Dave or David - It would be good to have a version or date for the manual on the 121gw page. Today I got the Kickstarter reminder on firmware (I already had 1.22) and manual updates. I tried to download the manual to see if it is newer than the 24 May version I have. The download was very slow (5+ minutes) so I just canceled.

Maybe the Kickstarter reminder caused a server overload? (Mostly joking about that).

In any case, if the manual version was listed I might not have needed to attempt the download.

Good idea, I'll add it now.

Edit : Added, your manual is out of date.

FYI the July 9 Manual link provides a Manual with 25 June on the front page.

Fixed, thanks

[bicycleguy]

That video link comes up unavailable.

I think I fixed it.

[techy101]

I see some people commented on this earlier, but mine showed up and I'm a little concerned about the viewing angles on the screen. I had to adjust the contrast up to the max value but it didn't help with the angle. Looking straight on, or sitting on the desk propped up on the tilting bale the display looks pretty hazy. This is accentuated if you're looking down at it. You really have to be looking at it from a very shallow angle, more or less looking up at the screen, to make it look crisp. In person it's much more pronounced than the pictures, but they were the best I could get and should get the point across. These pictures are with the backlight on, but there is no difference when it's off.

[bicycleguy]

Haven't seen quite this issue posted.  Appears the auto range doesn't work when the meter's batterys are at ~5.2V and try to measure something around 6V.  It is supposed to work with the batteries as low as 4.2

https://youtu.be/CXcKBs3Twv8

Worked ok with the measured batteries in the meter.  Will try some more experiments with different voltages.

After further testing it appears this auto ranging issue only happens in DC+AC mode and is completely unrelated to meter battery voltage.  I tested in AUTO DC with meter battery voltage down to 4.0V and auto ranging and indicated voltage was the same as with 6.2V meter batteries.  The low battery indicator came on at exactly 4.2V as the manual says.

In AUTO DC+AC regardless of meter batteries at 4V or 6.2V auto ranging hunts indefinitely when measuring around 6V.

In conclusion I'm happy again.  I can safely use NiMH batteries and I almost never use AUTO DC+AC (TRUE RMS) for DC anyway.

[firewalker]

But is it an issue or is it a limitation of the specific mode?

Alexander.