Compact 80.7 KB PDF for the 189NQ135, a single Schottky rectifier designation in the NQ range; the 135 suffix most likely means a 135 V reverse rating. Indexed as a schematic, the file is really expected to be a component datasheet. Technicians consult it for forward drop, current capability, surge limits and package dimensions when replacing a rectifier in a high-power converter. Open it with any PDF viewer and compare the physical part and its marking before fitting a substitute.
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.