Your laptop screen has a cable that connects directly to the motherboard. It is usually located where the bottom of the screen meets the laptop base. This cable can become loose over time or dislodged during a routine repair. It's very likely that a loose cable is the cause if the screen also flickers on an off when the lid is moved. Remove the faceplate to expose the cable and secure it to the motherboard.
The screen is one of the most important components on your laptop. But few computer users realize what goes on behind the scenes. An LCD screen is back-lit, which provides the illumination needed to make the images visible. If the screen suddenly turns black while open, the backlight has turned off prematurely. Failing hardware is often the cause, but it isn't true in every situation.
Damage to the outside of a laptop can also interfere with the connections on the inside. For example, if it is cracked near the hinges, the casing can place pressure on the cable every time you move the lid. Examine the case for damage and check all screws to be sure none are missing. Once you find the source, secure it with duct tape until you can get a professional to look at it.
Along the bottom edge of the screen is a switch responsible for triggering hibernation and sleep mode. The lid switch should move freely when pressed or it could get stuck in the down position. If this happens, power is cut off and not allowed to reach the backlight lamp. Use a can of compressed air to blow dust and debris from the area, then clean it carefully with a dab of rubbing alcohol and a cotton swab. Let it dry completely before re-assembling the screen.
The inverter is a flat board at the base of the screen that provides power to the backlight. It is hidden behind the plastic casing. Like the video cable, lid switch and backlight, it can only be seen if you take the display assembly apart. A failing inverter occasionally loses power, which causes the screen to go out. If the inverter or backlight bulb is bad, you can still see a dim image on the screen.
The video card is responsible for displaying the actual images on the screen. If the video card is the culprit, no image will appear on the screen at all. Connect the laptop to an external monitor; if it doesn't work, the graphics card is definitely the problem. You may need to access your video card settings via the Control Panel to enable the external display.
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