Can you post a pic of the screen?

It's not currently doing it, but if it does I will.

I'm getting all by laptop screen problems fixed these days. All the solutions end up costing between $100 and $200. That was one of them and I can't remember the part that need replacing. It was one of the cheaper ones, though.

You could try locating the most recent video driver from the Dell website, then updating the video driver you have now with the latest one. Use device manager to update the driver, once downloaded - just type "Device Manager" into Windows Help in the Start menu, then locate the video card and select "Update Driver." Even if there is no difference, choose to reinstall.

I found that Dell laptops really don't like being unplugged from an external monitor, then used on their own. They throw a wobbly and sulk, often just selecting a different setting at random, each time you power them up. My Dell panel (on a D620) was displaying a rather cool psychedelic rainbow diffraction pattern, even though all the settings seemed to be fine. Reinstalling the video card driver obviously *really* reset everything and it has been fine ever since.

The other cause for this could be a loose power or signal connector lead inside the laptop - one that is shorting against something else, or coming unplugged a little. If you're brave enough to take the cover off (most often accessed by removing the keyboard once you have removed the battery), you could just push home all the connectors you can find ....

Just make sure that you earth yourself (touch the metal on the case) before touching anything inside the computer, to avoid static discharge ... :-)

Heh, I'm an electronics technician and I won't even crack open a laptop any more. It's not the electronics; it's the damn case itself.

I am nowhere near technically minded enough to open the laptop, but I may ask ikkyu2 to take a look if updating the driver doesn't help.

This is an unfortunate case in which there is no instant gratification, since the problem's so intermittent, but I very much appreciate y'all's advice.

Thank you much!

Possible overheating?

If I were having this problem, I'd try giving it a little shake or bump to see if that had any effect. (but I wouldn't recommend anyone else try that :)

Can you post a pic of the screen?

I might be overthinking this, but if it's a power issue a screenshot may look normal while the actual backlight is causing the issue.

Of course you probably meant an actual picture of the screen, sorry. Even then there is no reall way of doing a decent troubleshoot for a problem like this.

Further thought makes me think that the actual backlight is the problem. You say that "Using the brightness controls will make the screen brighter or darker but don't solve the overexposed issue."

That sounds like it might be a capacitor problem. The caps that drive the backlight may be about to fail. Or the voltage regulator for the screen backlight. Regardless, it's not a user serviceable part. I'm pretty sure that you should contact Dell for service. Probably before it gets worse. Sorry I couldn't be more help.

Overheating might be a factor.

I'll see what Dell has to say.