I’ve been a witness of yet another bizarre thing yesterday. Sister brought her HP X360 with her and when she plugged it into a wall, screen went blank. As soon as I’ve unplugged it, screen came back. WTF!? I could clearly see laptop was still running just fine in the background, it was just the screen going all black.
I’ve predicted it has to do something with the power plan, but I didn’t think it would be what I found out later…
The reason for this is the reversed control for screen brightness!
Setting it to maximum brightness when plugged in like so…
…causes the screen to go blank when plugged into a wall socket because max brightness setting was actually maximum dimming in this case!
After trying the quick keys on keyboard to adjust brightness, same thing was observed, increasing brightness actually decreased the brightness of the screen and decreasing it actually made the screen brighter. I have no idea why this is happening, must be software or firmware bug or some missing special driver from HP that didn’t get installed with clean Windows 10 installation.
How to fix it?
Move the “Plugged in” slider all the way to the left and “On battery” somewhere closer to the right side. That should stop the screen going full black when you plug in the laptop.
So, before you throw your laptop into a bin or send it to service center, try this. It just might be the same (bizarre) issue. 🙂