What is DisplayPort? DisplayPort is a digital display and data transfer interface developed by the Video Electronics Standards Association (VESA) in 2006. Like its contemporary competitors, HDMI and Thunderbolt, it is a composite format capable of carrying video, audio, and data simultaneously.
Locked Home Screen. One meaning of the term locked iPhone refers to an iPhone with a locked home screen. All iPhones have a lock feature that allows a user to lock his home screen when the phone is not in use to prevent him from accidentally activating the touch screen while the phone is in his pocket.
So if you are facing iPhone Lock Screen unresponsive issue on iPhone 4S or 5 then you are in right place. You can try some quick fixes we are about to mention to overcome the issue. The main reason behind writing this post is because I too faced the issue on my old iPhone 4S which I use as a backup device.