: This is a primary source for "firmware dumps" used by electronics experts. You can find a dump for the TP.SIS231.PT85 board here. Note that while this link is for a Smart-Tech TV, it uses the exact same board.

: A "dump" file is generally meant to be written directly to the TV's SPI Flash chip using a programmer (like the CH341A or RT809F ), not via a USB stick.

: While official sites rarely provide "dumps" (SPI Flash images), you can check the Hisense Global Support or the Russian Hisense Support pages for standard USB firmware updates by entering your serial number.