What This Error Means

A “Firmware Update Failed” condition — also described as “bricked miner,” “miner stuck in boot loop,” “firmware flash error,” “upgrade failed,” or the miner becoming completely unresponsive after a firmware update attempt — means the firmware update process did not complete successfully and the miner is now running corrupted or incomplete firmware. The severity ranges from a minor inconvenience (miner reverts to old firmware) to a completely non-functional miner that cannot boot.

Firmware updates are critical for ASIC miners — they fix bugs, improve performance, patch security vulnerabilities, and sometimes unlock new features. But a failed update can leave the miner in a state where neither the old nor the new firmware is functional. The term “bricked” is often used but is misleading — most firmware failures are recoverable.

Common Causes

Power interruption during the update — The miner lost power while firmware was being written to storage. This is the most common and most damaging cause — it leaves the firmware image in a partially written, corrupt state.
Wrong firmware file — A firmware image for the wrong model, wrong hardware version, or wrong control board revision was applied. ASIC miners are highly model-specific — S19 firmware will not work on an S19 Pro, and vice versa.
Corrupted download — The firmware file was corrupted during download (incomplete download, network error, disk error). The file may appear valid but contains data errors.
Network interruption during web-based update — The browser connection to the miner was interrupted during the upload phase of a web-based firmware update.
Incompatible third-party firmware — A third-party firmware (Braiins OS, Vnish, HiveOS, etc.) does not support the specific hardware revision of the miner, or the installation process was not followed correctly.
Storage medium failure — The SD card (on SD-boot models) or NAND flash (on newer models) failed during the write process, making it impossible to store the new firmware.

Step-by-Step Fix

Important: Do not panic. Most “bricked” miners are recoverable. The key is to use the correct recovery method for your specific model.

Step 1: Assess the Current State

After a failed firmware update, determine the miner’s current condition:

Miner boots but firmware is old version — The update failed but the old firmware is intact. Simply retry the update.
Miner boots with errors or partial functionality — The new firmware is partially installed. Proceed to recovery flash.
Miner shows LEDs but no web interface — The control board is alive but the firmware cannot start the web server. Try SSH access or proceed to SD card recovery.
Miner shows no signs of life — This is rare from a firmware failure alone. Check power delivery before assuming the worst. Proceed to SD card recovery.

Step 2: Try the Web Interface

Attempt to access the miner web interface at its IP address. If the web interface loads — even with errors — you can attempt another firmware update through it. Download a fresh copy of the correct firmware file and try the update again, ensuring you do not interrupt power or close the browser during the process.

Step 3: Try SSH Access

If the web interface is not available, try SSH:

ssh root@[miner-ip]
# Default password varies by manufacturer and firmware
# Antminer stock: root / root (or admin / admin)
# Try common defaults for your model

If SSH connects, you can attempt a command-line firmware update:

# Upload firmware via SCP first
scp firmware.tar.gz root@[miner-ip]:/tmp/
# Then on the miner
ssh root@[miner-ip]
cd /tmp
tar xzf firmware.tar.gz
# Follow the specific update commands for your firmware

Step 4: SD Card Recovery Flash (Primary Recovery Method)

This is the most reliable recovery method and works even when the miner cannot boot:

Download the correct recovery firmware for your exact model and hardware version from the manufacturer’s support site
Verify the download — check the file size and MD5/SHA256 hash if provided
Write the recovery image to a microSD card using Etcher or Win32DiskImager
Use a quality microSD card (8-16GB, Class 10, from a reputable brand)
Power off the miner completely
Insert the recovery SD card into the control board’s microSD slot
Power on the miner
Wait 5-10 minutes — do not interrupt the recovery process
The miner will automatically detect the recovery card and reflash
When complete, the miner will reboot (LED patterns change — consult your model documentation)
Remove the SD card after successful recovery

Step 5: Verify the Hardware Version

If SD card recovery fails, double-check that you have the correct firmware for your hardware version. Open the miner and look at the control board. The hardware version is printed on the PCB — look for markings like “Xilinx,” “C55,” “BB,” followed by a version number. Using firmware for the wrong hardware version is a common recovery failure cause.

Step 6: Try Multiple Firmware Versions

If the latest firmware fails to recover the miner, try an older firmware version. Sometimes the latest firmware has compatibility issues with specific hardware revisions, but an older version will boot successfully. Once booted on the older firmware, you can then attempt a step-by-step upgrade.

Step 7: Serial Console Recovery (Advanced)

If SD card recovery does not work, a serial console connection provides the deepest level of access:

# Connect a USB-to-UART adapter (3.3V TTL) to the debug header on the control board
# Serial settings: 115200 baud, 8N1
# This provides boot console output and may provide U-Boot access
# From U-Boot, you can manually flash firmware via TFTP or USB

Serial console access requires basic electronics knowledge (identifying TX, RX, and GND pins) and a terminal program. This is the last resort before professional repair.

Advanced Diagnosis

Bootloader access: If the U-Boot bootloader is accessible via serial console, you have significant recovery options. U-Boot can load firmware from network (TFTP), USB, or SD card independently of the corrupted main firmware. The key is interrupting the boot process at the U-Boot prompt (usually by pressing a key during the countdown).

NAND recovery: On NAND-based models, if both the main firmware and the recovery partition are corrupted, the NAND chip may need to be externally reprogrammed using a NAND programmer. This is professional-level repair that involves physically accessing the NAND chip.

Third-party to stock firmware recovery: If you installed third-party firmware (Braiins OS, Vnish, etc.) and it has failed, the recovery path back to stock firmware varies by third-party firmware. Braiins OS provides its own recovery tools and instructions. For other firmware, an SD card recovery with stock firmware usually works, but some third-party firmware modifies the bootloader, complicating recovery.

When to Get Professional Help

Seek professional ASIC repair if:

SD card recovery does not restore the miner after trying multiple firmware versions
The control board shows no signs of life (no LEDs, no serial console output) — may indicate hardware damage beyond firmware
You cannot determine the correct hardware version or firmware for your model
Third-party firmware modified the bootloader and standard recovery does not work
The miner powers on but continuously reboots in a boot loop that recovery cannot break

D-Central Technologies recovers bricked miners of all models. We have firmware archives for every hardware revision, NAND programming capability, and serial console tools to recover miners that resist standard recovery methods. Submit a repair request here

Affected Models

Firmware update failures can affect any ASIC miner. Models that are most commonly bricked during updates include: S17 and T17 (multiple hardware revisions make version matching difficult), S9 (SD card wear causes write failures during updates), and any miner being flashed with third-party firmware for the first time. S19 and S21 series have more robust recovery mechanisms but can still be bricked by power interruptions.

Related Error Codes

SD Card Error / Boot Failure — Often coexists with firmware failures on SD-boot models
EEPROM Error — Firmware updates can trigger EEPROM corruption
Network Error — A partially booted miner may appear as a network issue
Chain X Only — Incorrect firmware can cause chain initialization failures

Frequently Asked Questions

Is my miner really bricked?

Probably not. True bricking (unrecoverable hardware damage) from a firmware update is extremely rare. In the vast majority of cases, the miner can be recovered through SD card recovery, serial console access, or professional NAND reprogramming. Even a miner that shows no LEDs after a firmware failure is usually recoverable — the firmware corruption may be preventing the boot process before LEDs are initialized.

How do I prevent firmware update failures?

Follow these rules: (1) Never interrupt power during a firmware update — use a UPS if possible, (2) Double-check the model and hardware version before flashing, (3) Download firmware from official sources and verify file integrity, (4) Use a wired Ethernet connection (not WiFi bridge) during web-based updates, (5) Close other browser tabs and applications that might time out the connection, (6) For SD card flashes, use high-quality cards and verify the write with a hash check.

Can I switch back from third-party firmware to stock?

In most cases, yes. Braiins OS provides a recovery tool that restores stock firmware. For other third-party firmware, an SD card recovery flash with stock firmware usually works. However, some third-party firmware modifies the bootloader or partition layout, which can complicate the recovery. Always follow the specific third-party firmware’s uninstallation instructions before attempting SD card recovery.

Should I update firmware if my miner is working fine?

Generally, if your miner is running well with no issues, firmware updates are optional but recommended for security patches. If your miner has performance issues, bugs, or known vulnerabilities, updating is more strongly recommended. Always read the firmware release notes before updating — some updates make significant changes that may affect your mining configuration. Keep a record of your pool settings before updating, as some firmware updates reset configuration to factory defaults.

Firmware Update Failed Fix — Bricked ASIC Miner Recovery Guide