Flashing red underneath is from the receiver - it's no longer bound to the transmitter. The manual on page 11 to 12 has the process. If that doesn't work then you may have killed the receiver.
The motor might be damaged, or it could be the electronic speed controller. If you are confident with soldering you could unsolder a known good motor and put it to the suspect controller. If the motor works, then the original motor is gone. If the known good motor doesn't work then the ESC is probably gone.
All of these parts are available as spares, though you may need to do some googling to find dealers who stock all. If you aren't confident in soldering then you may as well send it to a reputable dealer and pay for them to repair it.
Good luck!