Xperia z Phone is not booting and displaying anything

I was playing nfs no limits game on my xperia z c6602

It suddenly freezed and display gone off, when i tried to reboot the device

Holding power button , it doesnt boot

After learning few methods on internet

I tried to press power button + volume up button

Phone vibrated after holding those keys for 5 seconds it vibrated 3 more time

Button nthing came on the screen

Battery was 70% charged when i was playing

I tried to connet usb charger

Then it showed red notification light, i thought i was charging but

When i removed the charger notification light didnt turn off after hours off try nothing came to the screen

Pls help