PDF schematic of roughly 4.19 MB for Wistron board 14279-1; it appears identical in name and size to another entry for the same number. No model or brand is stated, so identify the laptop by the number silkscreened on the PCB. Wistron ODM boards with this numbering pattern are found in products from several brands. Technicians use such a diagram to follow power sequencing, locate fuses and MOSFETs on rails and confirm connector pinouts. Verify the board number and revision before trusting component values.
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 @ithinkhs_casediscussion. Enginerys does not host this file.
How to open a .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.