M8 Dead- No Response at all.

Hi,

While using my M8 all of a sudden the screen froze and after few secs the phone went blank.
Since then there is no response at all, only LED blinks(Red for few secs) sometimes when connected to a power source.
I've tried all the Power and Vol Button combos, nothing seems to work .
There is no vibration too.
When connected to PC it says"Qualcomm H-USB".
The phone is rooted.

Any suggestions or workarounds???

Thanks in advance!

Regards.