Meizu MX4 repair archive in RAR format, about 1.3 MB, whose name carries no detail beyond the phone model. Expect service material such as schematics or board drawings, but check the actual files after extracting. Diagrams for a handset like this guide measurements on the PMIC outputs, USB and charging path, and display backlight circuit when a phone is dead or partially working. Compare markings on the mainboard with those in the documents, as manufacturers sometimes revise layouts during production.
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 @SMART_PHONE_SCHEMATICS. Enginerys does not host this file.
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.