A 126 KB PDF filed under schematics, though its name, 1SS269, points to a semiconductor part rather than a circuit board. Under the Japanese JIS designation, 1SS marks a small-signal diode, so the document most likely lists maximum ratings, forward voltage, leakage and package dimensions. That information helps when identifying an unmarked or burnt diode, picking a substitute, or checking a measured diode-mode reading against spec. Any PDF viewer opens it, and the package code should be matched before soldering in a replacement.
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.