LCD Monitor on laptop goes dark, but not completely off

December 3, 2006 5:55 PM

My LCD screen on my laptop refuses to stay on.

I have a laptop (a Dell Insipron 8600 running XP, with which I have had no such problem before; in fact, it's been pretty maintenance free up till now).

My laptop goes dark after a very short time (between 1-5 minutes when running on battery, and right after startup when plugged in). This first happened last night overnight, so it's not an I-hit-the-wrong-key issue, and the screen is still "ghosting out" to the point where I can see what's happening. Also, the boot-up screens all show up fine, and it only goes dark when the desktop itself appears (or doesn't, in this case).

Running a second monitor off the back works fine (which is how I'm typing this), and I've installed the latest nVidia driver, for what that's worth. Is there something else I can do, or am I just screwed?

(Note: this seems like the same problem wendell had, except I've had this computer for over two years, so it's off warranty, and replacing the monitor would be rather more of a hassle.)

posted by chicobangs to computers & internet (9 comments total)

I don't have a lasting solution, but if your computer has a Fn-F7 menu, you may be able to learn the keystroke sequence to toggle the primary display off, then on, to give you a full-of-hassles coping strategy.
posted by Kwantsar at 6:10 PM on December 3, 2006

Sounds like the blacklight isn't working properly. If it's anything like my laptop, ebay should be awash with replacement blacklight parts, usually under $20. Find and download the servive manual for your laptop, which will walk you through the proceedure. Chances are that the only tools you'll need are a screwdriver and some care.

Failing that, the entire screen assembly could be replaced, but that's more expensive, and you still have to use a screwdriver, but there will probably be less fiddling with fragile bits.

Failing that, you could remove the backlight and backlight panel entirely, cut out a screen-sized hole in the back of your lid, and let sunlight shine through the LCD from behind. Not much good in the dark though :-)
posted by -harlequin- at 6:19 PM on December 3, 2006 [1 favorite]

The cold cathode fluorescent lightbulb that lights up the LCD display is dying, dying... They usually last about three years. Although, from the symptoms it almost seems like a cracked connection, that is knocked out whenever the laptop gets hot. But regardless, it's the backlight.

Replacement is not too difficult. Contact a local shop, or have Dell do it, or whatever. Or just live with a second monitor connected to the machine.
posted by jellicle at 6:49 PM on December 3, 2006

I found with a number of Toshiba laptops I had repaired was the invertors die out a lot. They are usually a small slim pcb located below (not behind) the screen, and replacing them usually does the trick.
posted by rc55 at 6:52 PM on December 3, 2006

I don't believe it's a cracked connection or a heat-related issue, because powering down & immediately back up brings back the boot screens just fine. (The boot-up screens for XP are always fully lit and okay. The screen only goes dark afterward, which tells me the problem is somewhere else.)
posted by chicobangs at 9:08 PM on December 3, 2006

Try a live boot CD. If the thing works in higher resolutions running off CD, you have at least ruled out hardware as a possibility. The fact that the Windows boot screens are lower res and lower color depth might mean the driver is screwy at higher settings. Longshot - hardware issue is more likely - but worth a try.
posted by caution live frogs at 9:54 PM on December 3, 2006

Seconding caution live frogs' resolution-dependent notion. See if setting your resolution to 640x480 and minimal colors lets it work. It would be weird if this is the case -- a videocard/memory or maybe even power supply problem ? -- but Windows being fine throughout bootup does imply that the problem is higher resolution / color.
posted by cps at 11:12 PM on December 3, 2006

The sensor that tells it when the lid is closed might be stuck. This happened to my mom when she put an american flag sticker on her Thinkpad, up near the hinge. Her laptop lives on a desk and goes months without being closed, so when she folded it up to take it to a conference, it was the first time in ages. The sticker got pushed in against the sensor and continued depressing the sensor even after the screen was opened again.

Upon arriving at the conference, the screen would flicker on powerup but not stay lit. Fn+Fwhatever would also flicker the backlight, and she could see screen contents with a flashlight so there was definitely something there. She didn't call me for what was obviously a hardware issue, so imagine her chagrin when she arrived home and, after inspecting the machine for a whole 14 seconds, I pulled the offending sticker off and the screen sprang to life.
posted by Myself at 9:13 PM on December 5, 2006

We had the same problem with our Toshiba, and it was the FL inverter as rc55 said. I think it was <$150 Canadian with labour.
posted by Yogurt at 1:14 PM on December 11, 2006