PDF schematic whose short name points to the A127F, most likely the Samsung SM-A127F, a variant of the Galaxy A12. The name gives no brand or revision, so check the title block inside to confirm the model and board revision. The 2.28 MB file should contain circuit pages useful for tracing power rails, checking for shorts and following charging and display signals. Any PDF viewer can open it. Verify that the board in front of you matches the document before measuring voltages or replacing components.
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 @uzb4422. 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.