The screen remains:
- Unresponsive buttons.
- Wont unlock (unresponsive screen).
- Stuck in another mode/application.
The iPhone could have been unplugged in the middle of doing an update or syncing data. Or the battery has drained and now will not respond. As well as this an iOS update may have failed/ become corrupted and need to be done again.
Have the iPhone:
- Plugged into the USB wall charger
- Press and hold the Power button on the top right hand of the iPhone and at the same time press the home button (main central button on the iPhone) together until you see this screen or a white apple logo:
This screen maybe up for awhile as its resetting the iPhone and recovering , most of your settings and data won’t be effected but this does depend on what has caused the iPhone to stop responding. While it is doing this leave to recharge fully if the battery was drained. If this works then you should go back to the slide lock screen and have a fully working iPhone.
Depending on what iOS you are using you may see different screens during this process, this has been tested up to iOS 5.1.1