For general inquiries, you can check the Akai Professional Downloads page, though they primarily focus on audio gear rather than television sets. How to Install the Update
The .rar extension indicates a compressed file, and part09 signifies it is the ninth piece of a split archive that must be fully downloaded to extract the internal .bin firmware file. Where to Find the Download
A common source for verified board software like the TP.SK506S.PB802 USB Firmware Google Drive Repositories: Some technicians share direct links, such as this TP.SK506S.PB802 Firmware Drive