Nighthawk MR5200 (M5) No Working At All

My MR5200 has stopped working all of a sudden. It will not connect to the internet despite saying it is. 

The MR started giving warnings on the device screen. Now it's stopped altogether.

Customer support will not help unless I pay (however it is still under warranty)

I've tried everything: Reboot, update firmware, checked all sims and tried new sims,