PDF schematic labelled with the IBM code name Yukon, about 1.67 MB. The name carries only this project name, without a model number, board number or revision, so identify the matching ThinkPad by comparing the title block and part numbers with your board. Internal code names like this are common on laptop design documents and usually appear on each sheet. The diagram is useful for tracing power rails, following signal nets across pages and finding component values when chasing a short or a missing voltage, and opens in any PDF viewer.
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.