Why does my Nokia Lumia keep flashing Nokia?

[Windows Central Question]

I turned my phone off. (Nokia Lumia 630) Now it keeps flashing the Nokia logo and vibrating. Its like it is caught in a loop. It is unresponsive to soft reset. I took the battery and Sim card out for awhile but once the battery goes back in the loop begins again. I've had the phone for approx 7 months. I like the phone and would like to resolve this. I'm not sure if it is running Cyan or Denim. Thank for any help.