Installing incorrect firmware can permanently "brick" your TV. Ensure your board and panel match exactly before proceeding.
Release the button when the standby light starts flashing (indicating the update has started). Download MT5522S PC822 3840x2160 AKTV4636S part03 rar
You can find these files on technical forums like Kenotrontv or specialized repair sites. Download MT5522S PC822 3840x2160 AKTV4636S part03 rar
Plug the TV into the power outlet while still holding the button. Download MT5522S PC822 3840x2160 AKTV4636S part03 rar