HP 7 G2, rooted, now won't boot up past powered by android screen.

[piefurz]

Not sure which operating system since it won't boot up now.  Rooted the tablet to get an app to run that provides a power off button on screen.  Now the tablet won't boot up past the powered by android screen.  Can't get into android menus to factory reset.  At one point after setting for a while it went to asking for language setting and network but alas I wasn't near a network and later the setup options went away.  Leaving it on now near a network to see if I can get back in again.  Any help would be appreciated.  The tablet had been acting up, freezing while playing solitaire.  Thanks

[piefurz]

Tablet finally got into the menu where I could factory reset it  and ended up with

E:failed to mount /cache (invalid argument)

E:Can't mount /cache/recovery/log

E:Can't open /cache/recovery/log

E:failed to mount /cache (invalad argument)

E:can't mount /cache/recovery/last_log

E:can't open /cache/recovery/last_log

E:failed to mount /cache (invalid argument)

E:can't mount /cache/recovery/last_install

E:can't open /cache/recovery/last_install

E:failed to mount /cache (invalid argument)

--wiping data...

wiping data stating

wiping /data

wiping 0 times

wiping 1 times

wiping 2 times

wiping data end

E:failed to mount /cache (invalid argument)

formatting /cache...

data wipe complete

Tablet stopped here, will have to restart to see results, took a long time for tablet to do this.