Maybe flashing your original Nor flash, and downgrade again. Will get you out of your loop.
That error means:
Update error 0x8002F281 Error with installing Firmware update. Check the connection of the Wifi/BT board.
Issue with the PS3 harddrive. 0x8002F281 Issue with the PS3 harddrive. Reboot system and use Recovery Menu options. If error persist, Format the hd on a pc, reinsert it to the ps3, install update (normal/recovery mode), format hd on install. If still not fixed: exchange harddrive.
Note: This error also comes up when trying to install a 1.5TB HDD as internal HDD.