How to unlock your Antminer stock firmware

What You’ll Need:

• A PC

• For CV and Xil control boards: a card reader and a microSD card (8GB or less)

• For AML control boards: a USB-OTG adapter and a standard USB-A flash drive

❗️Not sure what control board you have?
Check the label on the top cover of your ASIC miner. Most recent Bitmain models display the control board type clearly. Look for the line that says Ctrl_Board.
Here’s how to identify it:

• 7007, Xil — Xilinx (XIL) board, MicroSD slot

• CV1835 — Cvitek (CV) board, MicroSD slot

• Amlogic — Amlogic (AML) board, the only one with a MicroUSB port

• BB — BeagleBone (BB) board, usually has no MicroSD/MicroUSB port on the front

Step-by-Step Rollback Guide

1. Go to  QuantumHash Firmware page.

2. Find the correct recovery image matching your miner model and control board.

3. Download the appropriate recovery image to your PC.

(In this example, we’ll use Antminer S21 with an Amlogic board.)

4. Prepare your SD card or USB flash:

• Open My Computer, right-click on the storage device

• Choose Format

• Select FAT32 as the file system

• Use the default allocation size

• Click Start

5. Extract the downloaded recovery archive and copy all contents to the root of the freshly formatted storage device.

6. Make sure all files were copied correctly. Then safely eject the card or flash drive from your computer.

7. Turn off the power on your ASIC.
Insert the OTG adapter or microSD card into the appropriate port on the control board.
Then turn the power back on.

8. A green “Normal” LED should light up within 10–20 seconds after powering on.

9. Turn off the device again and remove the storage device.

10. Turn the ASIC back on.
Launch BTCTools and scan for devices.
You should now see the miner detected under the model name of the recovery you flashed. The pool settings will be empty.

11. Confirm the stock firmware version is now is earlierthan February 20, 2024.

All is done! Now you can proceed with QuantumHash firmware installation!