PDF listed as a schematic under the name 30ETH06, a code that matches the pattern used for power rectifier diodes rather than any motherboard. The name gives no brand, board number or revision, so open the 207 KB file to confirm its maker and contents. A document like this is typically used to look up forward voltage, reverse voltage and current ratings, package outline and pin assignment. Check that the marking on the suspect part matches before choosing a replacement for a power supply or inverter repair.
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.