Can't adjust brightness on M4800

[K4sum1]

I got a M4800 with a Quadro M2200, it's pretty nice but I can't seem to control the brightness from within Windows. If I use the hotkey I get the UI element of the brightness change but it remains at its current brightness. The power options slider doesn't work either. Doesn't matter if plugged in or not. Only the BIOS brightness slider appears to change anything for Windows. Oddly Linux Mint 21 runs at a very low brightness, and I can adjust it, but only down, down enough where the backlight just turns off.

 

[Aaron44126]

This is a common problem with an "unsupported GPU" in this system.  You should be able to set the brightness level in the BIOS.  If you're running with Optimus / graphics switching turned on, it should work but you might have to use the Intel GPU driver package from Dell, not the one built-in to Windows or from Intel's web site.  If you're running with Optimus / graphics switching turned off, I don't know if there is really a solution to this.  😕

 

[K4sum1]

Hmm, why have I not seen this discussed anywhere else? Also why is it an issue with this model? I remember my 8770W having no issues with the 980m when it worked.

[Aaron44126]

This sort of issue popped up semi-regularly on NBR back when these systems were "old enough to have GPU replacements done" but not yet "really old" (2015-2018 timeframe?).  There isn't a whole lot of discussion of the pre-7000 series systems here on NBT.