A 153 KB schematic-category PDF whose name, 60HFU, states no brand, product or board revision. The short alphanumeric code most likely identifies a component series rather than a motherboard. Opening it in a regular PDF reader will show whether it contains a pinout, an application circuit or ratings tables. When using it to diagnose a shorted or open part, measure the component out of circuit where possible, and confirm that its marking matches the series covered here.
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.