Part 83CNQ080A is the subject of this 207 KB PDF, indexed as a schematic but almost certainly a component datasheet, since the code follows the International Rectifier style for dual Schottky rectifiers and the A suffix marks a variant. No device or board is named. Technicians reach for such a sheet to confirm package, pin layout and ratings when checking a diode with a meter or sourcing an equivalent. The suffix matters, so compare it with the marking on the part you are replacing.
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.