PDF schematic of a PS-5161-1D1S power supply, a model code in the style of LiteOn's PS series, often used for desktop PC power units. The name gives no brand or wattage. Use the diagram to follow the standby circuit, PFC stage, main converter, output rails and supervisor IC when a unit fails to start or a rail is missing. Desktop power units store dangerous voltages on their primary capacitors, so discharge them first. Confirm that the label model and PCB markings match this exact variant.
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 @schematicslaptop. 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.