My laptop screen not showing anything even after powering on

@snehashish98898 start by connecting an external monitor and see if that displays anything . It is possible that this is related to a bad LCD screen. You also want to check if your screen is actually on but your backlights have not turned on. A simple check for that would be to darken the room and turn the computer on. Then use a flashlight and angle the light at the screen on different areas. Do that in a darkened room. See if you can make out shadows or shapes or even your desktop. If you do, then it is your backlight that has failed.

If you do not see anything or if an external monitor does not show anything, then it is possible that you are having an issue with the GPU on the motherboard or that your laptop is not loading it BIOS file.