Schematic PDF for the Samsung SM-M317F, the Galaxy M31s. At 4.41 MB it should contain a reasonable set of circuit drawings, likely covering power management, charging, the processor and memory, and peripheral connectors. Use it to trace missing supply voltages, find the source of a short or follow display and camera lines during diagnosis. It opens in any standard PDF reader, and searching designators is the quickest way to navigate. The name lists no board revision, so compare the revision on the PCB with the document.
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 @uzb4422. 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.