Can't wipe or factory reset Nexus 7 (2102) using multiple methods

I have a galaxy nexus and it's doing the same.

Can't reset - flash-all takes ages - appears to work then on reboot phone is exactly as before.

Phone starts OK and reboots anything from a few seconds to a few minutes of on time.

Really stuck....
 

Forum statistics

Threads
958,080
Messages
6,975,559
Members
3,163,988
Latest member
jrs369