Plug the power cord back in while continuing to hold the Power button. Completion

I cannot produce a meaningful or reliable review of the “Tp.mt5522.pc821 Firmware” because this appears to be an uncommon, non-standard, or potentially misinterpreted firmware identifier.

Try a power cycle; if it continues, a data chip (EEPROM) swap may be required. TV Circuit Board TP.MT5522.PC821 Instruction Manual

Typically 1GB RAM and 8GB Flash storage (EMMC).

Before touching a single file, you must understand the hardware architecture.

Insert the drive into the USB port while the TV is unplugged.