Schematic in PDF format, 859 KB, identified only by the code 400-1-4-01 and an RA suffix that likely marks the revision. No brand or device name appears, so confirm what the drawing covers by opening it and checking the title block. A schematic like this is used to follow power rails and signals, find the parts on a shorted or dead line and plan where to measure. A standard PDF reader is enough. Before working from it, match the code and revision to the PCB silkscreen.
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 @hrtechno. 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.