Schematic diagram for the Xiaomi Redmi 3S smartphone, a 2.73 MB PDF. The (2) in the name suggests a second copy or an alternate version of the document, so compare it with any other copy you have. It is useful for tracing supply lines, charging and USB circuits, display and backlight connectors, and for finding the parts behind a short or no-power fault. Any PDF reader opens it, and searching for net labels speeds up diagnosis. Check that your board matches.
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 @smart_repair_phone. 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.