Quanta ZW9 board documentation, revision 2A, provided as a 998 KB RAR archive. The name does not identify the laptop brand or model, so confirm the ZW9 code and the 2A revision on the PCB itself. Quanta is a contract manufacturer whose boards appear in notebooks from many brands. The archive most likely holds a schematic PDF, which helps with tracing power rails and signals, understanding the power-on sequence and picking the right points to measure during diagnosis.
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 @IT_SERVICE_WORLD. 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.