820-3126 – Apple A1311
820-3126 is the Apple main board used in the Apple A1311. 3 files are indexed for this board: 1 BIOS file, 1 schematic and 1 boardview.
File names mention revision A. The earliest file dates from October 2021 (Cyberlan Electronics, Schematics & Boardviews Archive and BIOS Archive).
BIOS dumps 1
Schematics 1
Boardviews 1
Board facts
| Board number | 820-3126 |
|---|---|
| Numbering | Apple board number |
| Revisions | A |
| First seen | 2021-10-02 |
| Source channels | Cyberlan Electronics, Schematics & Boardviews Archive, BIOS Archive |
| About the number | Apple logic boards are numbered 820-xxxx or 820-xxxxx; the trailing letter is the revision. |
Apple models for this logic board
| A-number | Model | Years |
|---|---|---|
| A1311 | iMac 21.5-inch | 2009–2011 |
A-numbers come from the file names; the model names and years are Apple's published identifiers.
Laptops that use 820-3126
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 |
| .brd | .brd boardview (Test_Link format) | OpenBoardView, FlexBV or BoardViewer |
| .rar | RAR archive | 7-Zip or WinRAR |
| .bin | BIOS image inside the archive (usually .bin) | a CH341A, XGecu T48 / TL866II Plus or RT809H programmer |
Questions
Which laptops use the 820-3126 board?
Files in the catalog link 820-3126 to the Apple A1311.
Is there a boardview for 820-3126?
Yes, 1 boardview file in .bdv and .brd 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.