My iphone 6 just keep rebooting. sometimes it starts up then it gets into reboot loop again. My device have never been jailbroken

My iphone 6 is stuck in reboot. sometimes it starts up and then 2 seconds after the home screen appears it goes into to reboot loop again. It have never been jailbroken. I am willing to try anything. My iphone have got screen replacement not original. so idk if apple can help?