To help diagnose the issue with your phone’s screen intermittently turning on and off, here’s a list of things to consider:

1. Check the power connections – are they stable and secure?
2. Try rebooting the phone and see if that helps.
3. Check if there is any software update available and install it.
4. Check if the issue is screen-specific or hardware-specific by testing it on a different screen.
5. Check to make sure the display drivers are up to date.
6. If all else fails, consider taking the phone in for repairs or replacing it.