Apple iphone4s/5/5s/5c upgrade IOS7 later electricity and text messages are always not access, another lock screen key failure

Problem phenomenon

National line IPhone5, upgrade IOS7 later electricity and text messages are always on, that is, the phone has been on the boot but the other people call the phone completely unresponsive, the other tip "temporarily unable to connect." SMS is also not received. What's the problem, wow? How to solve it?
In addition, the cell Phone lock screen key failed, but the phone in the warranty period, can be guaranteed?

Solutions

Two ways to resolve:
First, while holding down the home key + open the key, waiting for the device to reboot to see if the problem is resolved.

Second, enter the DFU mode to restore the device to see if the problem is resolved (remember to back up).
Note: If none can be resolved, it is recommended to make an appointment to the authorized maintenance provider or Apple Store for testing.