Avoid third-party "driver updater" software. They often bundle adware or outdated beta versions of the TPHV553pc821 driver that will re-introduce the fix loop.
After the fix, run a loopback test via Modbus register 0x40001 . A reading of 0x55AA confirms the bootloader and application are now correctly aligned. tphv553pc821 software download fixed
: If you're encountering issues, look at any error messages carefully. They often provide clues as to what might be wrong. Avoid third-party "driver updater" software
Insert the USB into the TV's USB port while the power is off. Press and hold the Power Key on the TV panel, then turn on the main AC power. tphv553pc821 software download fixed