Ensure your board version matches V59MS T9B exactly. Flashing a dump file with a different resolution (e.g., 1366x768 instead of 1920x1080) can result in a distorted image or a "no display" state.
To download the file, you should primarily look for it on official and dedicated firmware repositories. A dump file is a complete backup of the TV or receiver's flash memory, used to repair devices stuck in boot loops or with corrupted software. Primary Download Sources
Since this is a "dump" file, it is typically intended for use with a physical flash programmer (like the RT809F or CH341A) to write directly to the SPI Flash IC.