Hello Friends,
I have purchased Samsung Galaxy Core 3 months back. From past one week it was restarting again & again after each 5 or 10 minutes.
It was seriously annoying situation for me. Even after switching it off it was restarting.
due to this problem I have purchased new phone and removed SIM 2 from this phone.
From that time onwards phone is not getting restart. Then I realized this problem started the day I inserted 2nd SIM in this phone.
So you can also try to check by removing SIM 2 if you are using. May be it can solve the problem.
Thanks.