PDF of 127 KB filed among schematics and named 403CMQ080. The name does not identify any device or motherboard and instead follows the pattern of a power semiconductor part number. Expect a datasheet with package drawing, pin or terminal arrangement, maximum ratings and forward characteristic curves. Repair use includes checking polarity and reverse voltage capability when replacing a rectifier in a supply. Test the suspect part with a meter in diode mode and confirm the printed marking matches the code before substituting.
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.