Samsung schematic archive for the SM-A307FN model, the Galaxy A30s variant, packed as a 3.24 MB ZIP and labelled ok in the name, indicating the contents were checked. Extract it to view the service drawings, usually PDF pages covering power, charging, display, audio, cameras and RF. Technicians use these to trace rails, locate components and diagnose shorts or dead circuits. Confirm the model and board revision printed on the phone's mainboard match before relying on the pages, as regional variants 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 @phoneSchematics. Enginerys does not host this file.
How to open a .zip file
Compressed archive that every operating system opens without extra software.