PDF schematic for the IBM ThinkPad X61, 1.42 MB, with no board number or revision stated in the name. Its size matches another X61 schematic in the index, so it is most likely the same document saved under a slightly different name. Technicians use X61 drawings to trace rails, follow the charging and power-on circuits and pinpoint shorted components on this compact board. It opens in any PDF viewer. Confirm that the PCB markings match before taking measurements from the diagram.
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 @schematicslaptop. 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.