Lenovo E255 schematic in PDF form, with the name giving only the model and no board number, manufacturer code or revision. Check the title block inside the document against the markings on the PCB so you know it fits the board on your bench. Technicians use such a diagram to follow power sequencing, measure the expected voltages at each rail, locate fuses, MOSFETs and controllers, and track down shorts. The file is under 1 MB and opens in any standard PDF reader, where net names can be searched quickly.
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 @schematicslaptop. 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.