why does my samsung s3mini keep on turning off

[AC Question]

so i bought this phone about 2 years ago i swapped the battery 2 times before never had this problem before so basically every time i open it about 6-10 seconds later it restarts itself and it just keeps on happening over and over again.

 

[belodion]

A bad SD card? A faulty power switch?

Does it do it in Safe Mode?