Why my phone is powering off itself.

[AC Question]

Hey, I have samsung galaxy s6 of verizon SM-G920V. All was working fine and I updated it to the latest firmware provided by verizon from verizon upgrade assistant. Now, my phone doesn't boot up sometimes and when it get booted after a minute or 2 minute it turns off and when I try to restart it shows me samsung logo 2 times and turns off.
kindly help

 

[B. Diddy]

Welcome to Android Central! Try using that Upgrade Assistant, but choose the Repair option this time.