A schematic diagram. Shared as “红米4X三级维修指导V01_www.DeviceDB.xyz_.pdf” — a .pdf file, 3.13 MB.
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 @esquematicosespecialista. 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.
Any PDF readerSumatraPDFFirefox / ChromeFlexBV (links PDF to boardview)