HP archive labelled DVB 11A40-2 together with 48.4RI03.021, a number in the format Wistron uses for its board part numbers. The name gives no laptop model or file type, so check the contents, which may be schematics, boardview or firmware for that board, before using them. At 48.6 MB it likely holds several documents. Compare the 48.4 code and revision printed on the PCB with this one before relying on any of the data inside.
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 @azvoltagemap. 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