Firmware release 2.53 (build 20899) from 10 September 2019 for the SS-900HD NEW receiver, packed as a 4.13 MB zip. The NEW suffix suggests a later hardware variant, so check the unit carefully, since software for the older version may not suit it. The archive contents are not listed in the name. Repair technicians use such files to update receivers or recover boxes stuck at boot, by USB or with a flash programmer; back up the existing chip before any direct write.
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 @tamirkaran_chanel. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.
Back up your own chip before writing any dump, and match the full board number and revision. Flashing guide →