Disassembly and reassembly guide for the Samsung SM-A500G, an 831 KB PDF. It lays out how to open the phone, unplug the battery and flex cables, remove the board and refit components in the correct order. As mechanical documentation it does not show circuits; electrical diagnosis needs a schematic for this exact model. Following the documented steps lowers the risk of damaging the display or connectors. Check the model code on the label, because the A500G differs from the A500F and A500H variants.
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 @schematic_mobiles. 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.