HP ProBook 650 G1 archive for motherboard 6050A2566301, MB revision A04. The 6050A numbering is Inventec's pattern, so Inventec manufactured the board for HP. The name does not list the files inside; such sets usually contain a schematic or boardview for tracing rails, checking enable signals and locating components. Open the RAR with WinRAR or 7-Zip, and confirm the board number and A04 revision printed on the PCB match before trusting values or test points.
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 @ShareMan_Electronic_Files. 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.