Catalogued as a schematic, this 145 KB PDF is named only 403CNQ, giving no device or revision. Without a numeric suffix it probably describes a component family with several voltage grades rather than a single part. The content should include terminal identification, mechanical outline and electrical limits typical of a rectifier datasheet. It helps when servicing high-current supplies, confirming the common terminal and choosing a replacement with equal ratings. Match the complete marking on the original part to the variant table before ordering.
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.