Turning off display backlight via DDC breaks monitor OSD on Xiaomi Mi BHR4269GL

[salihinki]

Hi, I can't access the OSD on Xiaomi Mi BHR4269GL after enabling "Turn off display backlight when combined brightness is set to zero" and fully dimming the monitor. Pressing any of the physical buttons now results the backlight turning off for a few seconds and turning back on. Other DDC adjustments still work (brightness, contrast, etc). Attempted to use the factory reset DDC command, but it did not resolve the issue.

[waydabber]

Hmm. This seems to be a display specific firmware issue. Did you try turning it off and on? You might need to contact Xiaomi for instructions on how to do a hardware reset on the monitor.

[supermar1010]

I have the same issue with my Xioami 34" uhd monitor. It does not only affect this software but all of them. Something breaks in the monitor as soon as you use any ddc software. I haven't found any cure for it :/.

Some guy reported that uninstalling everything and unplugging the monitor worked for hiom, not for me unfortunately :/

[moyunkz]

I had a similar issue with my Xiaomi G PRO 27i while adjusting the BetterDisplay settings. What worked for me was using a DP cable, accessing the DDC Control, and selecting the Display Factory Reset option. This brought the OSD back. Hope this helps!

[mpkelevra23]

Confirming what moyunkz posted back in September 2024. The OSD on a Xiaomi G Pro 27i really can be brought back. I did it from Linux with ddcutil.

Mine broke after a DDC power cycle:

ddcutil setvcp d6 04
ddcutil setvcp d6 01

The first command returned DDCRC_VERIFY. Worth knowing: that does not mean the write failed. The byte did reach the firmware, it's only the read-back that didn't confirm it. Definitely don't retry the command when you see this.

After those commands the menu stopped opening. The joystick itself still works, a press blanks the screen for about a second and then the picture comes back, but no menu.

What fixed it:

ddcutil setvcp 04 1

That's VCP 0x04, Restore Factory Defaults, the same factory reset BetterDisplay calls Display Factory Reset. The menu worked again after it. It also released 0xDC (display mode), which had been stuck at 0x00 and refusing every other value.

Two things to keep in mind. The reset wipes brightness, contrast, color preset and RGB gains, so save them with getvcp first. And this is only the second known success on this model. salihinki in this same thread had the reset fail on a different Xiaomi, so it clearly isn't universal across the range.

[rm-killer]

Can you plz tell me how can i use this command in windows 11?

[rm-killer]

i used "control my monitor app" to execute the command. it didn't fix. just my monitor went black and back in under a sec and didn't fix at all

[ozp3]

1:1 exact same problem here. Pressing any button other than power button causes black screen for a second, then screen turns on again. I cant find any kind of solution. There is huge no no for xiaomi monitors.

[rm-killer]

did you find any solution? i have same problem.

[supermar1010]

I managed to fix my monitor, well it was definitely not me but claude doing it. So do use this at your own risk but it worked on mine.

For diagnosis I also used claude, it ran some tests on the monitor including inspecting the firmware of it. This required the monitor to be connected via hdmi (apparently via DP the I2C goes via a the DP controller instead of directly so some stuff is blocked).

This is the gist where claude wrote down all the findings and also a script to fix your monitor use this at your own discretion. i'm not responsible for any broken monitors, it worked on mine though!

https://gist.github.com/supermar1010/3e81e3f23ce16c826e383edbf9442351

[rm-killer]

Thanks to @supermar1010 i managed to fix my monitor as well. it was a little bit different and i was in Windows 11 as well. https://github.com/rm-killer/xiaomi-curved-34-osd-fix-windows
you guys can check it out and as always Do it with your responsibility.

[supermar1010]

Ohhh awesome! I'm happy that you also found a way!!!