I do recall an issue like this but I need to think of where I saw it.Yeah.. its got a full charge.. And when i hit the power button to unlock the phone ill i see is the status bar and my wallpaper.. No option to unlock the screen..
Try this in the meantime.
Boot into recovery, wipe cache and dalvik cache and reboot.
(To get into recovery---Turn off phone, wait a few seconds then, while holding volume down button-press power....you will go into bootloader and from there you can select recovery...then wipe )
