IBM schematic in PDF format labelled Rome with what appears to be version 4.0, about 1.68 MB. Rome is likely an internal project name, but the file name does not say which ThinkPad model it belongs to, so compare the title blocks and the board markings carefully before use. A schematic of this kind helps trace power rails, follow signal paths, verify component values and locate the source of a short. Any PDF reader opens it; check the revision noted in the drawing against the PCB.
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 @alischematics. 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.