Short 85.5 KB PDF named 30dps, listed as a schematic, with a name that looks like a part number for a discrete power diode rather than a board drawing. No brand, equipment or motherboard is identified. A datasheet like this normally lists reverse voltage, forward current, recovery behaviour, package and pin layout. That lets a technician confirm a failed component in a power supply and source an equivalent. The name is quite sparse, so compare markings on the original part before relying on it.
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 @cyberlanelectonik. 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.