Motherboard issue

[account_disabled]

Im using sony Xperia Z1. It has been only 4 months and suddenly my phone stopped working and automatically getting switched off. When I submitted to the service centre they told me that there is an issue in the motherboard. Also there is a small crack on the back cover of my phone. Is there any connection between the crack and the motherboard. What's the solution for this problem?

Please help.

Thanks!

I didn't find the right solution from the Internet.

References talk.sonymobile.com/t5/Xperia-Z1-Z1s/Motherboard-issue/td-p/1014642

Whiteboard Video