Laptop is running but screen is very very dark. can just make out the welcome screen

What computer? Laptop or desktop? What screen? Built in laptop screen, or external monitor?

From your description, we are guessing that the screen is still on and operating, but the light level is very low. This is different from the monitor not running at all.

First check your brightness controls, either on your keyboard or through your operating software to see if it was accidentally turned down.

For hardware problems, the most common reason for a screen to suddenly go dark is a failure of the backlight, the cable to the backlight, or the inverter / driver circuit that powers the backlight. Can you still see the operating system running on the screen even if it is dark? If it is super dark, you can try shining a flashlight on the screen to see if you can see normal screen activity. If the screen is active, that means that the video circuit is running, and the problem is in the backlight circuitry.

In laptops, this can be a result of the ribbon cable that goes through the hinge of the machine becoming unplugged, or broken.

hi

can you plug in another monitor to the video plug on the side of your laptop?

if the monitor works but your laptop screen stays dark your laptop screen needs to be replaced .

If the monitor is also dark then the LCD screen is ok but the inverter needs to be replaced
lcd connect to laptop
inverter
lcd screen replacement
cheers

Sounds like the screen is burned out. You need to replace it.

If it's plugged in and not running on batteries then it sounds like your screen is going out on you.

Have you tested it with an external monitor?

I would say you either have a damaged inverter board or screen baclight lamp. Usually the inverter board fails in one of the following ways:

1. When you turn on the laptop, the screen lights up for a short period of time and then goes dark. You still can see an image but it is very dark, almost invisible and definitely not usable. When you restart the laptop, the screen lights up and then goes dark again. The laptop works fine with an external monitor.
2. Your laptop turns on but the screen remains dark all the time. You still can see a very dim image outline. The laptop works fine with an external monitor.
3. The laptop screen works fine for hours or even days, but sometimes it goes very dark as it mentioned above. When you restart the laptop, the screen works fine again.

Inverter failure symptoms are very similar to backlight lamp failure symptoms and in most cases you cannot tell which one is causing the problem until you replace either the inverter board or the backlight lamp. From my personal experience, inverter boards fail more often than backlight lamps. If you have to guess, replace the inverter first.

go to control panel, personalize, display setting & change setting to 1280 by 800 pixels and chande color to the highest 32 bits

OR go to control panel, then click device manger, click display adapter make
Sure you have just one display driver install

Hi Yacob

First Run a diags on the dell laptop. You can initiate it by pressing fn+power button together and start the laptop. It will go to the diags screen. Tell me if the diags pass or not and then we will troubleshoot further.
Thank you
Rakesh
Dell Laptop Expert

try to install a vga monitor in the (db 15) Blue video conector...see if your laptop works fine...

then shoud be the inverter of your LCD that is not working anymore..the backlight is dead...that´s why the dark screen is driving you crazy!

see the model of your laptop and try to buy it on ebay..there are a lots of inverters there!
Good Luck!

Do you get the same result if its plugged in or running off battery? Try holding down the "FN" key or function key and using one of the Function keys i believe its F6 on the sony's to brighten up your screen if that doesn't work try downloading and reinstalling your video driver and finally you may have a video card issue