ThinkPad schematic in PDF form, labelled NN-D491 in the name. That is most likely a typo for the LCFC board NM-D491, but confirm it against the title block. The RAR archive is 2.64 MB and no revision is stated. A circuit diagram like this shows power rails, sequencing signals, connector pinouts and part values, which is useful for working out why a rail is missing or which IC drives a signal. Any PDF reader opens it. Check the board number and revision on its pages against your 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 @schematicslaptop. Enginerys does not host this file.
All sources (3)
The same file was posted more than once. If one link is dead, try the next.
| Channel | Posted | |
|---|---|---|
| @schematicslaptop | 13 Dec 2023 | Open file on RM Schematics |
| @cyberlanelectonik | 23 Jul 2026 | Open file on RM Schematics |
| @schematics_bios | 14 Aug 2026 | Open file on RM Schematics |
How to open a .rar file
Compressed archive — the usual wrapper for a schematic + boardview pair or a BIOS + EC set.