Archive covering the IBM ThinkPad R50, R51 and R52 notebooks in one 2.4 MB RAR package. These models are grouped together, but the name lists no board numbers or content type, so extract it with 7-Zip or WinRAR to see what is included. Service documents of this kind help diagnose power faults, trace rails and signals, and locate components and test points. Different variants within the R50 family can use separate system boards, so confirm the board number on your PCB matches before using the drawings.
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 .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.