Audio schematic for the Samsung SM-A21s covering microphone, loudspeaker and earpiece, PDF, 3.82 MB. The sheet maps the audio paths, typically the codec or amplifier connections, microphone bias lines and speaker outputs. It helps with complaints like callers not hearing you, no ringtone or a silent earpiece: measure mic bias, check speaker contacts and trace the lines for open circuits. Open it in any PDF viewer. Confirm the board is from an SM-A21s before matching parts.
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.