In the recovery menu, use the physical buttons to select "wipe data/factory reset" to clear corrupted system files.
If the system is "bricked," you might need to bridge specific pads on the motherboard to enter Mask ROM mode for a deep flash. Hk.t.rt2843p639 Firmware
For specialized files and community-tested versions, technicians often visit Kazmi Elecom or Dipelectronicslab to find board-specific dumps. In the recovery menu, use the physical buttons