Update package for the A8700 receiver carrying version V8.29 from 26 October 2021, about 11.3 MB in zip form. Sister packages with the same version exist for other models, so check you have the A8700 one. Unpack it to obtain the image and any notes, then apply it to upgrade or revive a box stuck on startup. Confirm the board matches and read the current flash with a programmer before writing to keep a fallback.
The button opens the matching file on RM Schematics, or a source page if it is not catalogued there yet. The original attachment is from @tvsoftwareworld. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Built-in OS tools7-Zip