Laptop screens are made from LCDs -- liquid crystal displays.
You're working on your laptop when suddenly, the screen starts to flicker. Whether it happens only intermittently or frequently, it's a problem that cannot only be a nuisance, but can also point to larger problems within your laptop and its LCD -- or liquid crystal display -- monitor.
Faulty Cables
Even though laptops are designed to give you the ability to work away from your desk, eventually you'll have to recharge your laptop. If you notice the screen flickering only when you have it plugged in to the battery, examine the power cord. A crimp or other damage to the cable could cause the screen to flicker. Also, a loose cable connection on either end of the cord could be to blame. Look to see if the port into which you plug the cable is secure; if the port is jiggling, it could contribute to the problem.
Low Battery
Just as a faulty battery cable can be the culprit behind a flickering laptop screen, a low battery on the laptop itself can also be to blame. If you notice the screen flickering only when the laptop's battery is running low, try plugging the device into its charger.
Slow Refresh Rate
Your computer's refresh rate determines the rate at which your computer sends information between the CPU and the monitor. A low refresh rate means this information is sent less frequently than with a faster refresh rate. To see your laptop's refresh rate, access the control panel inside the "Start" menu. Click on the "Display" or "Monitor" tab, and look for the section called "Refresh Rate" or "Refresh Frequency." View the refresh rate options from the drop-down box, and try different rates until you eliminate the flicker problem.
Backlight Problems
LCD monitors -- on televisions, laptops and flat-panel computer screens -- rely on a backlight to illuminate the liquid crystals, creating the image. A flickering screen could indicate a problem with your monitor's backlight. A piece of equipment called an inverter supplies power to your backlight; if the inverter's connection to the backlight is loose or damaged, it could cause the screen to flicker. This is a problem you can't solve on your own; you should contact a professional laptop repair person to look into the issue.
Video Card
To see if the problem is because of your laptop screen, or the laptop itself, connect it to an external monitor. If the flicker is no longer present, the issue is with your laptop's LCD screen; a replacement screen will likely eliminate this problem. If the flicker persists with the external monitor, the problem may be a faulty video card. This card's purpose is to generate images and transfer them from the computer's CPU to the screen; if there is a problem with the card, the image will be broken, discolored or may flicker on and off.