At 126 KB, this PDF is titled 80CPQ150 and, despite the schematic category, most likely contains the datasheet for that rectifier, following International Rectifier part naming. No device, brand or motherboard is stated in the name. It is useful for confirming the pin arrangement, package drawing and limit values before testing a suspect part with a meter or ordering a substitute. Open it in any PDF reader and compare the full marking on the component with the title first.
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.