Samsung Galaxy Luna is going wonky

[Tamriel_Bound11]

My girlfriends phone is just going all wrong. She's had it for a few months, brand new, no problems. Now all of a sudden it was continuously turning off and back on, off and on, off and on. She decided to take the battery out and pop it back in. When she swiped to put in her pin, the screen turned gray and the phone would not respond. We have no idea what went wrong or what to do.

Please help.

 

[Tamriel_Bound11]

Figured it out. Something was wrong with the external SD card that was corrupting the boot-up process. Booted up and restarted the phone, then turned it off again. It is now working properly with the SD card in place.