Unhappy [Q] stuck at "google screen", failed to mount cache (invalid argument)

my nexus 7 failed to boot, stuck at "google screen", can boot into bootloader, can boot into recovery mode.

try erase or format cache partition from PC with fastboot command, failed.
try sideload a new zip, also failed to mount cache partition.

I had searched around, it happened to others also, but i can not find a solution.

anyone know what is the problem?

Thank you.