Default Possible hardware failure

My wife let her battery die....it was dead for several weeks. Now it only boots to the Google screen. I can get to fastboot mode but I'm unable to do anything. It was never unlocked/rooted.

I was trying to unlock it so I can put a ROM on there hoping that would fix it. I get an error trying to unlock it but it doesn't give a reason. It says something like remote failed ().

Bootloader version 4.18.
Think its hardware related?
Any suggestions?

Sent from my Nexus 7 using XDA Free mobile app