Schematic in PDF form for the LCFC board NM-B421, compressed into a 10.9 MB RAR archive; the name gives no laptop model or revision. LCFC is the Lenovo-owned design house that numbers its boards NM-xxxx, so this belongs to a Lenovo notebook. The diagram lets a technician follow power-on sequencing, trace rails like 3V and 5V always-on, check enable and power-good signals and identify parts around a short. Verify the board number and revision silkscreened on the PCB before relying on component values.
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 (5)
The same file was posted more than once. If one link is dead, try the next.
| Channel | Posted | |
|---|---|---|
| @schematicslaptop | 18 Nov 2021 | Open file on RM Schematics |
| @pepeelectronica | 26 Apr 2022 | Open file on RM Schematics |
| @schematics_bios | 25 Jul 2026 | Open file on RM Schematics |
| @schematics_bios | 2 Aug 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.