NM-B891 – Lenovo ThinkPad T490S
The NM-B891 (LCFC) motherboard is found in the Lenovo ThinkPad T490S and Lenovo ThinkPad X390. ChambersDesignInc.com has indexed 12 files for this board — 10 BIOS files, 1 schematic and 1 boardview.
File names mention revision 2.0 or 1.0. The BIOS dumps are 32 MB images. ODM project names: FX390 and FT491. First posted in July 2020 in BIOS Archive, Schematics & Boardviews Archive and Cyberlan Electronics.
BIOS dumps 10
Schematics 1
Boardviews 1
From the uploader
FT491 FX390 NM-B891 REV 2.0 2019-01-28 32MB
MEC1663
TYPE-C
FT491 FX390 NM-B891 REV 2.0 2019-01-28 BIOS & TYPE-C & MEC 32MB &1MB & 256KB BIOS WORKING 100%
Board facts
| Board number | NM-B891 |
|---|---|
| Designed by | LCFC |
| Platform group | NM-B |
| ODM project | FX390, FT491 |
| Revisions | 2.0, 1.0 |
| BIOS chip size | 32 MB |
| Flash chip | MX25L25633F |
| CPU generation | Intel 8th gen |
| First seen | 2020-07-15 |
| Source channels | BIOS Archive, Schematics & Boardviews Archive, Cyberlan Electronics |
| 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-B891
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 |
| .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-B891 board?
NM-B891 is an LCFC board number used by Lenovo.
What BIOS chip size does NM-B891 use?
The BIOS images for NM-B891 are 32 MB. Flash chips named in the files: MX25L25633F.
Is there a boardview for NM-B891?
Yes, 1 boardview file in .bdv and .tvw format.
Which laptops use the NM-B891 board?
Files in the catalog link NM-B891 to the Lenovo ThinkPad T490S and Lenovo ThinkPad X390.
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.