NM-B291 – Lenovo Yoga 920
NM-B291 is the LCFC main board used in the Lenovo Yoga 920 and Lenovo Yoga 920-13IKB. 4 files are indexed for this board: 2 BIOS files, 1 schematic, 1 boardview and 1 EC firmware image.
File names mention revision 1.0. BIOS images are 8 MB. ODM project name: DYG60. First posted in March 2022 in Schematics & Boardviews Archive, Cyberlan Electronics and BIOS Archive.
BIOS dumps 2
Schematics 1
Boardviews 1
Board facts
| Board number | NM-B291 |
|---|---|
| Designed by | LCFC |
| Platform group | NM-B |
| ODM project | DYG60 |
| Revisions | 1.0 |
| BIOS chip size | 8 MB |
| First seen | 2022-03-03 |
| Source channels | Schematics & Boardviews Archive, Cyberlan Electronics, BIOS Archive |
| About the number | LCFC is Lenovo's joint venture with Compal; its main boards use NM- numbers and sub-boards NS- numbers. |
Laptops that use NM-B291
- Lenovo Yoga 920
- Lenovo Yoga 920-13IKB
What these files are for
A BIOS dump is a full image of the board's SPI flash chip. It is written back with an SPI programmer when the original firmware is corrupted, after a chip replacement, or to recover from a failed update. Read and save the original chip first: serial number, DMI data and the Intel ME / AMD PSP state differ between boards.
A schematic is the circuit diagram of the main board: power rails, power-up sequence, component values and net names. It is the reference for measuring voltages and tracing a fault.
A boardview is the component placement map of the PCB: click a part or a net and the viewer highlights where it is and what it connects to. Used together with the schematic to find test points.
Tools to open these files
| Format | What it is | Open with |
|---|---|---|
| .bdv | Honhan .bdv boardview | OpenBoardView, FlexBV or Honhan BoardViewer |
| PDF schematic | any PDF reader; Sumatra PDF and Foxit handle large schematics well | |
| .rar | RAR archive | 7-Zip or WinRAR |
| .tvw | Tebo-ICT .tvw boardview | FlexBV or Tebo-ICT View |
| .zip | ZIP archive | 7-Zip, WinRAR or the built-in Windows extractor |
| .bin | BIOS image inside the archive (usually .bin) | a CH341A, XGecu T48 / TL866II Plus or RT809H programmer |
Questions
Who designed the NM-B291 board?
NM-B291 is an LCFC board number used by Lenovo.
What BIOS chip size does NM-B291 use?
The BIOS images for NM-B291 are 8 MB.
Which laptops use the NM-B291 board?
Files in the catalog link NM-B291 to the Lenovo Yoga 920 and Lenovo Yoga 920-13IKB.
Are these files free?
1 of the posts are marked VIP or paid in their source channel; the others are ordinary posts. ChambersDesignInc.com does not host or sell files.
Is there a boardview for NM-B291?
Yes, 1 boardview file in .bdv and .tvw format.
Where do the download links go?
Each button opens the original public Telegram post the file was shared in. ChambersDesignInc.com only indexes and cross-references those posts.