iphone 4

[lionsandbulldogs]

My phone was working fine and all of a sudden now the screen is black (as if the phone is turned off).  I cannot answer calls when it rings and obviously cannot text or do anything else with the phone,  the battery had a full charge at the time this happened.

[#2]

Hold down the on/off button on upper right side together with the large home button in the middle until you see the Apple logo.

Then release both buttons and the device will reset.

http://www.apple.com/support/iPhone

Good Luck