Please do try these troubleshooting steps that may help in identifying the issue.
- Start by doing a hard reset, remove the battery (if not built in) and AC adapter then press and hold the power button for 20 seconds then boot it back up.
- If these doesn't work connect an external monitor and see if you'll get a normal display from it because if you do that means it could be a problem with the display.
- Open your laptop and reseat the ribbon cable that connects the display to the motherboard.
- If the external monitor will produce the same line and grey screen that means it the graphics card that has the problem.
- Do call in the manufacturer for a repair if it's still under the factory warranty.