How do I stop my Windows screen from fading to black?

Question

I have a Windows 7 laptop, which I run connected to an external screen. For some reason, within the past three weeks, whenever the screen becomes especially dark for a few seconds it fades completely to black.

Here's an example of happens:

1. I minimize all windows. The screen shows my desktop, which is currently blank (black). All of the desktop icons are visible, as is the start button and the toolbar at the bottom of the screen.
2. Immediately (within 1 second) the screen starts fading to black, turning pitch black within 3 seconds.
3. Moving the mouse does nothing to restore the screen.
4. If I do something like hit the Windows key on my keyboard or alt-tab to bring up another window, it immediately fades back in.

Some other oddness: this has to do with the brightness of the screen. Setting a bright background stops it from happening, while navigating my web browser to an all-black page causes it to happen. If I get just the right level of darkness, it will fade out about halfway and then flicker until I change the screen.

Another interesting thing: if I have both the laptop and the desktop screen mirrored, and navigate to an all-black page, only the desktop screen fades.

What's going on?

Answer 1

It will be because of a setting in the external display to adjust the screen brightness automatically based on the content. Different brands have different names for this function, such as ASUS Smart Contrast Ratio (ASCR) or Samsung's MagicBright. Disable the feature in the display's settings and you should be right to go.

Answer 2

Could be a graphical driver conflict.
Intel® HD Graphics Driver - Download Center
But check Power-supply, cables and all that stuff as well for good measure.

Funnily enough, a workmate had the same problem last week in her office. Her screen was fading while she was using a (selfcoded) application that uses some google-earth functions. If this application was minimized (to the background) everything was working well, but it randomly started fading evertime the the application has been in the foreground/active.
So i can imagine your problem.
To be honest, i don't know what exactly solved that problem, but we verified if all cables were plugged correctly and installed another driver version as well and this have been working since.