Charging and data circuit schematic for the Samsung SM-A02S, a PDF of roughly 3.70 MB. The page covers the USB connector, charging path, overvoltage protection and data lines, which are the usual suspects when a phone will not charge, charges slowly or is not recognized by a computer. Follow VBUS from the port through protection components to the charger IC, check for shorts to ground and measure the data lines for continuity. Open it in any PDF viewer and verify the exact handset model before swapping parts based on it.
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 .pdf file
The standard format for schematics, block diagrams, power-sequence charts and service manuals.