Have my tablet been bricked?

Hi.
My tablet is ASUS Transformer Pad TF303cl.
After doing of the following tasks, Asus logo appears but boot animation doesn't but rather screen becomes black and turns on and off continually.
fastboot erase config
fastboot erase cache
fastboot erase firmware
fastboot erase ADF
fastboot erase factory
fastboot erase vendor
fastboot reboot
Because it is possible to go to fastboot mode, I did factory reset and reflashed stock firmware by 'fastboot flash update UL-K014-WW-11.4.1.34-user.zip', but my problem has not resolved.
What's the matter? Is my tf303cl tablet bricked? What can I do?