SD Card Flashing
SD card flashing restores an ASIC while bypassing the web interface: the control board boots from the card and rewrites itself from scratch.
How it works
Control boards have a boot-from-card mode: you write an image to a microSD, insert the card into the slot on the board, power the ASIC on, and it flashes itself. The password and the state of the old firmware don't matter, which is why this works when nothing else does.
Typical reasons: a forgotten or changed password, a board bricked by a failed update, a hang at boot, a return from third-party software to stock. In essence it is reinstalling the system from a flash drive, only for an ASIC.
The image must match the board rather than the ASIC model alone. One model can carry boards of different revisions and even different makers, and an image for the wrong revision either won't start or will start crooked. The marking on the board itself matters more than the label on the case.
Preparing the card is easy: a microSD of a few gigabytes, FAT32, image files in the root with no nested folders. After a successful flash, pull the card out, otherwise the next power-on sends the whole process around for a second lap.
The short version
| What you need | microSD, FAT32, image files in the root |
| What doesn't matter | password and state of the old firmware |
| The key condition | image for the board revision, not the case label |
| How to spot success | by the LEDs, usually a couple of minutes |
| After flashing | pull the card before rebooting |
Step by step
Identify the board: open the case and read the marking on the control board itself, then hunt for an image for that exact board.
Write the image to a FAT32 card, files in the root. Any healthy card of a few gigabytes will do.
Power the ASIC down, insert the card, switch it on and watch the LEDs as the image's instructions describe. Usually that is a few minutes of blinking.
Power off, pull the card, power on. The ASIC comes up with factory settings and the factory password, then it is the usual pool setup.
An example from the workshop
An ASIC arrived after a failed update: power is there, the network never comes up, the web interface is dead. Board marking, the right image, a card, five minutes of a blinking LED, and the ASIC greets you with the factory login page. Without SD mode that board would have gone to the programmer.
Related terms
Where to go next on the site
Software
- Software firmware
- Bitmain Stock Firmware firmware
Hardware
- ASIC Miner knowledge base
Questions and answers
Will my pool settings survive an SD flash
No, the board returns to factory state: pools, password and settings have to be entered again. That is the price of a clean recovery.
The ASIC ignores the card, what's wrong
Most often the image doesn't match this board revision, or the card isn't formatted as FAT32. Less often the slot itself or a dead board is to blame, and then it is off to the repair bench.
Can I update this way all the time
You can, but there is no point: regular updates go through the web interface. SD mode is an emergency tool and a way back to stock.
How the terms connect
Every link in the chain is clickable. Orange marks where you are now.
Looking for an ASIC miner
The catalog holds 212 models. You can compare them by hashrate and by joules per terahash, then plug your own rate into the calculator and see what stays in your pocket.
Page written and checked by Denys Klimchuk. Updated .