Hacking up a Astroai dm6000ar

[DmA]

Hello EEVblog!
I have a astroai dm6000ar multimeter that I bought a while ago, i love the thing, really cheap and a well rounded beginners multimeter with all the types of measurements you can need starting off. The only thing I wish i could change the light up display. I was wondering if anyone can help me out on finding a way to keep that lighting on. Preferably using the same method to turn it on should also turn it off (holding the light button). Any help would be great!
I know its not ideal due to battery drain, but using it as if it's on my bench all the time would be nice to have a fully controllable light switch on. If anyone knows of where i could get the schematics too would be a great start (I am having a tough time finding any form of schematics for this thing)!

[coromonadalix]

well  you could use an microcontroller to do the task, in the past i saw someone doing this on a uni-t meter

googling may help  find it again, or maybe here on eevblog ?

For a start   we would need to know the meter chipset, maybe something could be done at this level ?

[DmA]

Thanks for the response!
So i have good news and bad news. Good news is that the actual LED that lights up the display is super easy to get to. Worst come to worst i'll just rig up a small switch in the back with a resistor to turn on and off the LED. Now what i ideally would like to do is change the actual code that runes that function. As seen in the picture with the red and black trace tracking shows that its connected to that microcontroller it looks like right next to the buzzer there is a RX and TX (yeah i also see that there is a SMD resistor missing). I also recently bought a USB to TTL board so i can get in to it but after that i am pretty clueless.
Now for the bad news... The actually chipset was completely lasered off so i have no information on the actual chipset... so even if i do get in with the USB TTL board working on it i am pretty much flying blind after that...
Also you said you saw people mess around with similar things, i would be awesome if you can send me a link to it, maybe i could find a similar way to change those settings (auto-off and LED timer). The auto-off and LED timer are the only 2 real things I wanna change.

[coromonadalix]

Sold under kuman wh5000a  name too

Well,  youll have to google search 6000 counts dmm chipsets, not many comes up,  your ic has 64 pins   not the 100 pins i see on many suggested models

There's   3  brand who pop's up :  Cyrustek and Fortune Semiconductor  and Hycon

Could be an DTM0660L   very poor infos on that one
Datasheet : http://www.kerrywong.com/blog/wp-content/uploads/2016/04/DTM0660DataSheet.pdf


You'll have to do a schematic of your meter and try to check if it fits the pdf pinout




and some video of your meter :
I think there was an info in the part 2 ??

some hacks
https://www.eevblog.com/forum/testgear/uni-t-ut61e-backlight-mod-with-touch-sensor-(tutorial)/

https://www.dev-eth0.de/2017/11/12/ut61e-backlight/

http://www.kerrywong.com/2016/03/19/hacking-dtm0660l-based-multimeters/





cant help you more on this