Samsung S5303 PDF document, 2.77 MB, labelled Comp, which most likely refers to component placement or layout pages. No board revision appears in the name. Layout drawings show where each resistor, capacitor, connector and IC sits on the PCB, so faults found on the schematic can be located physically for probing or replacement. Any PDF viewer opens it, though zooming is useful for small designators. Before replacing anything, confirm that the S5303 board in hand matches the layout and revision shown in the document.
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 @tamirat_moobile. 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.