Hi,
Please do try these troubleshooting steps that may help.
- Start by doing a hard reboot, remove the battery and unplug the AC adapter then press and hold the power button for 20 seconds then try booting it up again.
- If the same problem will persist, connect an external monitor and see if the same problem will persist on it.
- If you'll see the same problem on the external monitor that could mean that the GPU is faulty already.
- But if the display is normal on the external display the problem may lie on the built in display.
- Try to open the laptop and check the ribbon cable that connects the LCD to the motherboard.
- Disconnect both ends from the motherboard and LCD then put it back in just to make sure it's seated properly.
- If all these will not work that means it needs to send for a repair to HP if it's still under the factory warranty.