PDF schematic for the A21s smartphone, model code A217F, which matches Samsung's SM-A217F numbering. The name gives no board revision. Phone schematics are used to trace power rails from the PMIC, check charging and USB circuits, follow display and camera connectors, and locate filters or capacitors that cause a short. Since the same model can ship with different board versions, compare the PCB markings with the schematic and confirm reference designators before replacing components.
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 @esquemaseletricos. 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.