Schematic for the ASUS K54LY laptop in PDF form, 674 KB in size. The name gives only the model, with no board revision, so compare the revision printed on the motherboard to the one on the schematic title block. Circuit diagrams like this let a technician follow power rails, check the power-on sequence, find pull-ups and signal paths and identify component values while diagnosing faults. Any PDF reader opens it, and its text search helps locate net names and reference designators quickly.
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 @cynetitsolution. 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.