ASUS schematic covering the X409FA, X409FB, X409FJ and X409FL models, provided as a 2.96 MB PDF. These suffixes usually reflect graphics or configuration options on a shared mainboard, so note which parts are populated on your board. No revision is stated in the name, so compare the drawing against the REV marking on the PCB. Technicians use it to follow power rails, check sequencing, locate the charger and VRM controllers and diagnose shorts. Any PDF reader opens it.
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 @afsschematicfree. 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.