Screen displays NOKIA. The phone neither turns off

[WPCentral Question]

The phone screen shows Nokia it is not even allowing me to restart. It was fine when I kept it for charging an hour back.

 

[RumoredNow]

Try a Soft Reset... Hold the Volume Down + Power buttons until the phone vibrates and reboots (about 10 seconds). You won't lose data.

If that does not work... you will have to reset, which can lose data. There is a chance to restore your cloud backup during the set up phase.
FAQ - How can I recover/reset/restore my phone software? - Microsoft - USA