These are the most common problems which affect laptop LCD screens and cause them to go completely black. This is general troubleshooting information only. Have your computer diagnosed by a knowledgeable technician if you don’t feel comfortable performing this procedure. The following is a list of common problems which create a blank or black laptop LCD screen; there are others that create the same symptom.
Burned Out LCD Bulb
A laptop computer LCD screen has a long light bulb which illuminates the screen and when this bulb is working properly, even though the laptop screen itself is still completely fine. Make sure that the “function” key wasn’t pressed to lower the light intensity. Check your computers manual for instructions.
Bad Video Card
Connect the laptop to an external monitor to make sure the motherboard is working properly. Your computer should start-up normally, including all the lights; however the screen will be completely black and will show faint images or none at all. The video card is working if an image appears on the external monitor.
An inverter is simply a part in a computer which makes DC (Direct Current) into AC (alternating current). When a laptop inverter fails, it doesn’t produce the amount of power necessary to ignite the CCFL lamp located inside the LCD screen. If you can’t see the background of the LCD screen with a flash light, there is a possibility the inverter is the problem. Newer laptops have , which don’t use an inverter.
I recommend that this only be done by someone who has good knowledge and is comfortable with opening up the laptop.