Re: my iphone6 dos'nt light up when calls arrives somtimes why
Hi. Welcome to the forums and sorry for the delay in getting back to you!
If the screen is still failing to light up even after a full restore and setting the device up as new then you should contact Apple.
Whilst I personally believe this is a software issue that should be fixed during a restore/set up as new it could be hardware which they will look into for you.