A 108 KB PDF listed as a schematic and titled 1SR124-400A, a code in the style of a discrete semiconductor part number, with the 400A suffix identifying a specific variant. The name mentions no device, board number or revision. Use it as a quick component reference for polarity, electrical ratings and footprint when a part is shorted, open or being swapped for an equivalent. Any PDF reader opens it. Make sure the marking on the physical part, including the suffix, matches 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.