hmmm it;s prob not the screen
My guess is that it's either the chip or the ribbon.
If it's under warranty have those putz's fix it.

Thanks... but the warranty is already over...
Any tips on repairing it myself?

It's not likely that you can fix it yourself. The problem is probably electronic, rather than mechanical.

Hi. The problem may be fixed by reinstalling the latest video drivers. And if u can check the line appears even on the bios screen i.e., tap on f2 key at dell logo at the startup of the sys. If u have the green line even in the bios screen then the lcd is gone bad and it has to be replaced.
And the latest drivers of the video adapters is available at www.support.dell.com

Yup it is on there all the time. Guess i might have to buy a new one.
Thanks guys.

I told that with such confidence because i am a dell techinician, working for DIS Hyderabad site.
U can before going for a replacement of the lcd once try reseating the lcd cable as i understand the replacing the lcd is a very costly affair.
Have a great day ahead.

any tips on reseating the ribbons? what should i do?

It's not unusual for a ribbon connector on a mass-produced piece of gear to not be fully latched, or for the ribbon to be not fully poked home when it was latched, or for the ribbon not to be straight in the connector. Any of these conditions can cause problems.

The ribbon is connected to the printed circuit board via a ribbon connector. The ribbon connector consists of two parts, body and latch. The ribbon enters the connector body through a slot in the latch. The latch itself has "ears" or tabs for finger grips on either end of the long dimension. Grip the ears, not the ribbon, and (gently) pull the latch out, away from the body until it stops. This releases the ribbon. Pull the ribbon from the connector and look at it to make sure that it's not kinked, torn or ragged and that the metal contacts look shiny. If you want to clean it, isopropyl alcohol and a cotton swab works best. Rubbing alcohol, while widely available, is not suitable for this purpose--it's 30% water. The easiest way to get near-pure isopropanol (about 98%) is to go to an auto-parts store and get an isopropanol gas dryer such as Iso-Heet. Note: Don't use a methyl alcohol dryer--methanol doesn't work as well as a solvent (the same goes for your gas tank, for that matter). It's easy to tell one from the other -- methanol dryers are cheaper and have a skull-and-crossbones poison warning on the bottle, ispropanol is less toxic, so it has no poison warning.

Once you are satisfied that the ribbon itself is whole, hale, hearty, and clean, you can plug it back in through the slot. Make sure that the ribbon is straight and pushed all the way in, but don't force it. Once it's poked home, gently hold it in place so it doesn't shift--then gently press the latch back into place by applying even pressure so that it, too goes back into place straight. That should do it.

If TallCool1's suggestion doesn't help any. (although it should...) then it is very possible that it is in fact the screen. I have an Inspiron 8200 myself, which is the same chassis style, and have had other such issues with my screen. (Mostly in the hinge sensor for open/close) I have read numerous times about people having issues with the I8x00 series screens on varioues news groups, and even heard it from Dell. I have not pursued getting a replacement screen for mine, as it isn't that troublesome... yet, but I beleive they are somewhere in ballpark of $400-$500. Someone please correct me if I am wrong.