First part of a split RAR set with A226B firmware, U5 binary, build A226BXXU5BVH2, OS12. Begin extraction with this 1.80 GB volume after collecting part2 and part3 into the same directory; a missing or corrupt volume will stop the process with a CRC error. The name does not specify the package style, so review the contents before choosing a flash tool. Confirm the phone model and U5 binary level, and keep a backup of NVRAM or EFS data so the IMEI survives the flash.
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 @mrepairo. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.
7-ZipWinRARThe Unarchiver (macOS)