Xiaomi Redmi 9C schematic in PDF, about 2.6 MB. The diagrams let a technician follow battery and charging circuits, PMIC outputs, display and backlight lines, and audio paths, which helps when diagnosing no-power, no-charge or no-display faults. Component designators in the schematic can be matched to the board to find capacitors, inductors and ICs. Open it with any PDF reader. Compare chip markings on the board with the document first, since Redmi models sometimes come in hardware variants.
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.