Press and hold the on the TV panel (not the remote) while plugging the power cord back in.
Insert the USB drive into the TV's USB port (use USB 2.0 if available). Download 43SU128 49SU131 55SU134 Firmware part02 rar
: These firmware updates are usually split into multiple parts (e.g., part01, part02). You must download all parts into the same folder on your computer before attempting to extract them. Press and hold the on the TV panel