Screen darkened after a crash?

I just accidentally pulled my laptop cable. It's an older gaming laptop with Windows 10 that doesn't run for ten seconds without a cable.

After the cable was pulled, there was an attempt to plug it back in quickly to avoid a midgame crash, but unsuccessful. When it came back on, the screen stayed at the same (darkened) brightness level as it was just before the crash. This has never been the case before, and I can't get the screen bright again. My second monitor is completely normal.

I'm really happy about any help.

Why don't you swap the connecting cables between the two monitors? If it is still the case, "Monitor 1" has probably "said goodbye".

Does the brightness control no longer work at all or does it work to reduce the brightness but not increase it to the maximum?

Unfortunately, I don't have two monitors, but rather a screen from the laptop and a monitor connected to the laptop.

With the brightness control I can't change anything, not darker or brighter.

Take out the battery. If that works.

Do you use the corresponding keys on the keyboard and it just doesn't work with them or have you tried the Windows slider and it doesn't work with it either?

https://support.microsoft.com/...58fc007041

In that case: Can the slider not be moved or can it be moved but without affecting the actual brightness?

Shut down the computer and boot it without an external monitor. If the computer does not run properly, boot it into repair mode. To do this, switch it off again using the power switch two or three times in a row during booting. A blue screen with white letters appeared. Under Troubleshoot / Advanced Options, select Startup Repair. Windows will now try to fix problems on its own that prevent a successful start.

The slider can be moved, but unfortunately does not change anything. The corresponding keys would be F9 and F8 if I'm correct, but unfortunately they don't work either.

The battery is firmly inside as far as I know, but I'll ask again.

I'll give it a try, thank you!

Too bad. I have an older notebook here that turns the monitor down to save energy. Since the battery was out, it has been working perfectly.

Understand. I would think of two things to do:

Reinstall the graphics driver on suspicion, restart and hope that it will bring something: https://fossbytes.com/how-to-fix-windows-10-brightness-control-not-working-issue/

To find out whether it is a software or hardware problem, one could boot a Linux live system (loads into the RAM and does not change anything on the hard drive) and see whether the problem occurs there. If you need help with this, please let me know, all you need is an empty USB stick.

What was the solution to the problem?

The answer from Colles. Boot the computer without the external monitor.