Schematic for the IBM ThinkPad A31, provided as a PDF of about 1.00 MB. The name lists only the model, with no board number or revision, so verify the identifiers on the motherboard before trusting values or connections. Such a drawing is used for tracing power rails from the adapter input, following enable and power-good signals during startup, and identifying which part pulls a rail to ground. Any PDF viewer opens it, and searching for net names or reference designators speeds up fault finding.
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.