Schematic in PDF form for a Lenovo E40, around 1.38 MB; the name gives no motherboard number or revision. It appears to be the same size as another E40 file and may be a duplicate copy. Open it in any PDF viewer and read the board number from the title block, then match it with the marking on the PCB, as one model may use more than one board. Technicians use it to follow the power-on sequence, locate MOSFETs and regulators on a dead rail and check signal paths between chips.
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.