my iphone 4 not turn on after update to 6.1.3

have the same problem, seems like a bug of new iOS

Try and reset the device by holding down the home and power button for 15 to 30 seconds while the device is plugged in to power. In a few moments you should see the silver apple, let the device start normally after that.

for some reason, with this update - all my data got deleted and i can't see my previous backups