Here is a list of parts that need to be checked:
1) The Backlight:
Also known as the CCFL Bulb. When this component goes bad, the screen will no longer light up. The easiest way to tell if this is the problem is to take a flashlight and point it at the screen while the computer is on. Do you see a faint image? If so, your backlight bulb may have gone bad.
The backlight (or CCFL bulb) may be broken. If this is the case, the screen will not light up when the computer is turned on. The best way to test this is to point a flashlight at the monitor while the computer is on. If you can see a faint image your backlight bulb may be broken. However, a backlight that is not lighting up could mean a broken LCD inverter if you have an LCD screen. The LCD inverter is responsible for powering up the backlight bulb. If it is broken, your backlight won’t receive any power and thus will not turn on. NOTE: LED screens do not have an inverter so don’t worry about inverter problems if you have an LED screen.
There may be a problem with your motherboard. Specifically, the problem is usually with the motherboard Graphics Processing Unit (GPU) chip. If your GPU chip is not working, your monitor won’t be receiving any signal from the computer. The best way to test if this is the problem is to connect your laptop to an external monitor using a side connector (all laptops will have an external monitor connector of some type). If your picture shows up on the external monitor then the problem is NOT with your motherboard. If no image shows up, you will most likely need a new motherboard, or a new laptop.
3. LCD Cable
There are numerous symptoms of a bad LCD cable such as a screen flickering on and off, or a screen lighting up with no visible signal from the computer. The LCD cable connects your LCD screen to the motherboard. To get to it we will need to open up the laptop to get to the cable. Try fiddling with the cable so see if there are any changes to the image. If this is the case, make sure the cable is properly connected. If there is no change in your image, you may need a replacement cable. Try testing out a new cable to see if your picture is restored. If this is the case the problem is solved.
4. LCD/LED screen
Once you have tested the above, it may be that your screen is simply broken and you will need a new one. Before buying a whole new screen, if it is possible, you should test your screen in another laptop to see if it works. If it works, it may be a rare problem that was not covered in this guide.
Hopefully on of these four common problems was your problem and your problem has been solved. If your problem still hasn’t been solved, one of our genius Newtons Nerds technicians will employ a wide range of tests to diagnose your problem.