Do not turn off the power during the update process.
Disclaimer: Firmware flashes are done at your own risk. Ensure the main board ID ( MSD6A638-T8E2 ) matches exactly before applying. Download MSD6A638 T8E2 Toshiba 43U7750 170207 zip
42.5" Toshiba 43U7750 - Specifications - DisplaySpecifications Do not turn off the power during the update process