After some confusion when turning on the phone with a low battery warning and flashing screens, upon restarting the phone stuck with the Samsung logo staring at us.
In recovery mode clearing the cache didn't fix the problem and a factory reset didn't either. Of note there was a message that never left the scene of the crime at the bottom that said E:failed to mount /efs (Invalid argument)
Tried Kies and connected by choosing the Firmware Upgrade and Initialization, which worked but still stuck at the Samsung screen. (Tried twice)
Tried two versions of Odin and flashed stock firmware which worked we know because the boot was different with no splash screen, then stopped at the Samsung logo again.
Any suggestions that someone with limited tech can try, or is the phone a lost cause.
Thanks
Samsung Galaxy GT-I9300T