Schematic PDF, 3.06 MB, for the Y540 laptop with an NVIDIA N18E-G1 graphics chip, as stated in the name. No brand or board number appears, so open the title block to confirm the motherboard code and revision before use. The diagrams help diagnose GPU power faults, missing rails and dead display outputs by tracing nets from the regulators to the graphics chip. Any PDF viewer opens it, and searching net names speeds up work. Check that your board's GPU variant matches before applying values.
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 @LaptopsBoardview. 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.