Here is a 570 KB PDF catalogued as a schematic whose name is simply 28010, without any brand or board identifier. Nothing more about the device can be read from the name, so the first step is to open it and see which part or circuit it describes. Documents named this way commonly hold a datasheet for one integrated circuit, covering pin assignments, electrical limits and application diagrams. Before working from it, match the top marking and package of the chip on your board to the part shown in the document.
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.