IBM ThinkPad R31 schematic in PDF, a compact file of about 1022 KB. Only the model appears in the name, with no board number or revision, so verify against the labels on your system board before relying on part values. Repair work benefits from such drawings when tracing power rails, testing the charger circuit, following signals from connectors to controllers, and locating components that may cause a short. Open it with any PDF reader and use text search for reference designators and net names while probing the board.
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.