After dropping your laptop, the physical damage to the screen or other components may cause the display to malfunction. To determine the cause of the screen issue, you must troubleshoot your laptop. If the damage is minimal, you may be able to make the repair yourself, but extensive damage will require the assistance of a professional.
Inspect the Screen
Pick your laptop off and turn off the power. Inspect the screen for damage by opening and closing the screen to make sure that it can easily move. Look at the screen for any cracks or areas of damage. If the screen shows outward signs of damage, take the computer to a retailer or contact the manufacturer for repairs.
Plug in the laptop and turn it on, noting what happens with the screen. You may see no display, or you could see a faint image or skewed image on the screen. If you can not see anything on the screen, test the computer by connecting it to an external monitor, such as one from a desktop computer. If the display on the external monitor is working perfectly, the problem lies within the display of the laptop. If you can't see the image on the external display, the root cause of the issue is deeper than the display.
If you can see a faint image on the laptop screen, or if the issue is that the image on the screen won't stay, the problem could be a damaged inverter or backlight. Try adjusting the brightness level on the screen if possible to rule out a damaged brightness button. Contact a computer repair service or the manufacturer to have the laptop repaired.
If the motherboard was damaged when you dropped the laptop, you may not see anything on the screen when the laptop is on or when you connect it to an external monitor. Motherboard damage may also appear as a white or colored screen, lines across the screen, or other images that don't make sense. Replacing the motherboard is a task that you should leave to a computer professional.