Huawei schematic in PDF form for a model named s7 Vogue, 4.18 MB; the name carries a website tag but no board number or revision. A circuit diagram like this helps locate power supply lines, charging and display circuits, connectors and test points when diagnosing a dead or partly working device. Any PDF reader opens it, and searching for part designators speeds up work. Before trusting part values or pinouts, confirm the exact model and PCB version of the unit, since variants under similar names can differ.
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 @mobileshematic. 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.