What causes laptos to not show display despite showing that they have switched on?

Step 1:
The display on your laptop is the interface through which you interact with and control your computer. If it is not working, your laptop will become virtually impossible to use. A laptop is a computer, and like all computers is subject to both hardware and software problems that may affect the display. Before taking your laptop in for repair or getting rid of it, you should first check the display yourself to see if it needs to be replaced.

Check the laptop's battery and power cord. If the laptop is out of power, the display will not work. This usually happens if the power cord is unplugged and you were unknowingly running your laptop on battery power. Check to make sure the power cord is plugged in and that the laptop has power. Many laptops also turn off the display if it is being powered by its battery after a period of nonuse. Touching any key will usually turn the display back on if the battery is not drained. Restart your computer. If a software program is stuck or malfunctioning, it may cause your display to stop functioning. Press and hold the "Power" button on your laptop to reboot your computer. If the problem was a malfunctioning program, the display will turn on after the computer restarts. Check the brightness level of the display. If the level is too low, the screen will appear dark. The brightness controls are usually located on two function keys, such as "F9" and "F10." Look for sun or light icons on the keys. Press the key with the larger icon to increase the brightness level. Alternatively, on some laptops hold the "Fn" key while simultaneously pressing the "Up Arrow" key to increase the screen brightness. Check the display closed switch. Many laptops have a small button that senses when the LCD screen is closed and puts the laptop in sleep or hibernation mode. If the switch gets clogged with dirt, it may get stuck in the closed position. This will result in dark display even when the lid is open. The switch is usually located near the hinges of the lid. Spray the switch with a can of compressed air to loosen the dirt so that it will resume its normal operation. Plug an external monitor into your laptop. If the problem is not software related, the external monitor will display the laptop's screen. Connect the monitor by plugging the cable into the VGA, HDMI or DVI port on the laptop. Press and hold the "Fn" key while simultaneously pressing the "F8" key. The video output will be directed to the external monitor if there is a hardware problem.

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