Author Topic: Amazon Do Multimeters Now  (Read 44845 times)

0 Members and 1 Guest are viewing this topic.

Offline Kosmic

  • Super Contributor
  • ***
  • Posts: 2554
  • Country: ca
Re: Amazon Do Multimeters Now
« Reply #150 on: March 26, 2023, 01:29:39 am »
Why is there glue on the protection diodes?

Cheap corona dope substitute ?
 

Offline JOSM

  • Contributor
  • Posts: 21
  • Country: de
Re: Amazon Do Multimeters Now
« Reply #151 on: April 04, 2023, 06:47:27 am »
Small detail about the 90DM890, the Bluethooth module is missing and the option is not in the setup menu. So, there's no way to connect to meter to phone or PC.

To compare against my RND 355-00010 (also a CEM DT-989 twin):
 

Offline Kosmic

  • Super Contributor
  • ***
  • Posts: 2554
  • Country: ca
Re: Amazon Do Multimeters Now
« Reply #152 on: April 05, 2023, 04:21:34 pm »
Small detail about the 90DM890, the Bluethooth module is missing and the option is not in the setup menu. So, there's no way to connect to meter to phone or PC.

To compare against my RND 355-00010 (also a CEM DT-989 twin):

I wonder if this one is made by CEM too. The board is somewhat similar but clearly not the same. Can't find any reference to DT-9589. Maybe a clone ?
 

Offline Kosmic

  • Super Contributor
  • ***
  • Posts: 2554
  • Country: ca
Re: Amazon Do Multimeters Now
« Reply #153 on: April 05, 2023, 04:24:30 pm »
Talking about the Amazon 90DM890 (CEM DT-989), if someone is looking for the password for the calibration menu and calibration procedures, poke me. I was able to get my hands on everything.
« Last Edit: April 05, 2023, 04:46:30 pm by Kosmic »
 
The following users thanked this post: JonnhyK

Online Kleinstein

  • Super Contributor
  • ***
  • Posts: 15159
  • Country: de
Re: Amazon Do Multimeters Now
« Reply #154 on: April 05, 2023, 06:40:16 pm »
Small detail about the 90DM890, the Bluethooth module is missing and the option is not in the setup menu. So, there's no way to connect to meter to phone or PC.


Why is there glue on the protection diodes?

The diodes look like the clamping diodes for the current ranges. With overcurrent these diodes can run quite hot - worst case this may be enough to unsolder them, which would be bad. They are supposed to fail (if at all) short, not open. The glue may be there to keep the diodes in place even of the solder gets soft. The part where the glue is applied is a connection anyway. So it would not be so bad as the glue later on turns a bit conductive when old.
 
The following users thanked this post: JonnhyK

Offline aeberbach

  • Regular Contributor
  • *
  • Posts: 238
  • Country: au
Re: Amazon Do Multimeters Now
« Reply #155 on: May 09, 2023, 08:33:40 pm »
I have one of these but the LCD is not quite right:



Figured I would open it up one day and reseat a cable and all would be well but it is not a reseatable cable:



The nearest pair of contacts are blobbed together but I don't think it could be that, could it?



Anyone know what the LCD is? No markings. I might replace it if it is cheap.
Software guy studying B.Eng.
 

Offline KungFuJosh

  • Super Contributor
  • ***
  • Posts: 3166
  • Country: us
  • TEAS is real.
Re: Amazon Do Multimeters Now
« Reply #156 on: May 11, 2023, 10:51:16 pm »
The nearest pair of contacts are blobbed together but I don't think it could be that, could it?

Check if the blob has continuity to ground; that might be on purpose. Or a big sloppy mistake. 🤷
"Right now I’m having amnesia and déjà vu at the same time. I think I’ve forgotten this before." - Steven Wright
 

Offline mwb1100

  • Frequent Contributor
  • **
  • Posts: 572
  • Country: us
Re: Amazon Do Multimeters Now
« Reply #157 on: May 12, 2023, 12:34:08 am »
Dave did a video a couple years ago about why pins might be intentionally shorted (24 minute video!) .  Might help you determine if that's the case here.

 

Online JonnhyK

  • Newbie
  • Posts: 2
  • Country: it
Re: Amazon Do Multimeters Now
« Reply #158 on: December 20, 2024, 05:01:37 pm »
Talking about the Amazon 90DM890 (CEM DT-989), if someone is looking for the password for the calibration menu and calibration procedures, poke me. I was able to get my hands on everything.

MODEL AMAZON COMMERCIAL 90DM890
BOARD DT-989-V1.5-A1-M4
FIRMWARE 1.10
S/N 220111833

CALIBRATION PASSWORD FOUND:

ONE ZERO ZERO ZERO

1 0 0 0


please kindly quote my reply adding if ur calibration password match or if u found different pwd

PLEASE add your board version - fw version - rebrand model or original CEM DT-989
 
The following users thanked this post: EEVblog, skander36

Offline skander36

  • Frequent Contributor
  • **
  • Posts: 898
  • Country: ro
Re: Amazon Do Multimeters Now
« Reply #159 on: December 20, 2024, 05:53:52 pm »
Thank you!
Password works.
FW. ver. 1.10
Board is not clear - DTD989 V1.5?
Amazon Comercial
« Last Edit: December 21, 2024, 09:25:20 am by skander36 »
 

Online JonnhyK

  • Newbie
  • Posts: 2
  • Country: it
Re: Amazon Do Multimeters Now
« Reply #160 on: December 21, 2024, 03:22:48 am »
Thank you!
Password works.
FW. ver. 1.10
Board is not clear - DTD989 V1.5?

copy.

PLEASE ADD IF YOUR MODEL IS AMAZON COMMERCIAL OR CEM OFFICIAL.

and share with other owners the result of my efforts :-)
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf