Dell schematic shared by the Latitude E5270, E5470, E5570 and Precision 3510, covering the SMDPC15H platform named in the file, as an 8.6 MB PDF. The DSC tag likely points to a discrete graphics build, but confirm it against the GPU pages before relying on that reading. Technicians use this set of drawings to trace power rails, check the power-on sequence and locate parts tied to a short or a dead circuit. Verify the board number on your PCB, since one design covers several models.
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 @afsschematicfree. 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.