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This is one of the strangest things I have ever seen.

I have an HP Elitebook 8460p and recently updated my Windows 8 to Windows 8.1.

Now when I have certain windows open and focused (it's always different, sometimes it's chrome, sometimes it's the control-panel and so on, there is no clear pattern) the backlight of the screen is completely turned off - when I take a torch and point it to the screen or hold it to a bright-light source I can see there is still a picture there you can even work (or better said you cuold if you'd see anything). When I tab to certain other windows the screen goes back to normal back light - I can then tab back to the other window and the backlight will be turned off again.

I have no idea what's going on and also no idea what information you need. The display-adapter I got is the AMD Radeon HD 6400M - I tried updating to the newest driver but that didn't help.

Here's a video of the whole thing:

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I have a HP EliteBook 8460p. I've had the same annoying problem for several months already (after I upgraded to Win 8.1). It appears that every time I plug the AC adapter the screen brightness goes to a full 100% and then it shuts off. So here's the solution that worked for me.

Control Panel > Power Options > Change Plan Settings > Change Advanced Power Settings > Display > Display Brightness.

Change the Plugged In percentage to 95% instead of 100%.

Now, every time I plug the AC adapter the brightness goes to 95% and the display does not shuts off.

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up vote 0 down vote accepted

I realized that it only occurs when there is too much "white" (the color) on the screen. I installed the Windows 7 driver for my graphic card and everything works again...

Please refer to this thread for details.

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