Comprehensive reference for all Antminer error codes, LED status indicators, and fault messages. Includes severity, common causes, quick fixes, and links to detailed troubleshooting guides for every error.
Antminer ASIC miners report errors through the web UI status page, kernel logs, and LED status indicators. Understanding these error codes is critical for fast diagnosis — each code points to a specific subsystem and narrows down the possible causes.
This guide covers every known Antminer error code organized by category, along with severity ratings, probable causes, and recommended actions. It applies to all Antminer models including S9, S17, S19 series, S21 series, T-series, and L-series.
Web UI SSH (Kernel Log) SSH (Miner Log)
Navigate to your miner's IP address in a web browser
Log in (default credentials: root / root or admin / admin)
Go to "System" → "Kernel Log" or "Miner Status"
Error messages appear in the status table and in the log output
The web UI shows the most recent errors and the current status of each hashboard, fan, and temperature sensor.
# Connect via SSH ssh root@ < miner-i p > # Password: root (or admin, depending on firmware) # View full kernel log dmesg # Filter for errors only dmesg | grep -iE "error|fail|fault|warn" # View real-time log output dmesg -w The kernel log contains hardware-level messages including chain detection, voltage errors, and temperature faults.
# Connect via SSH ssh root@ < miner-i p > # View the main miner application log cat /tmp/log/bmminer.log # View real-time miner log tail -f /tmp/log/bmminer.log # Check chip frequency and status cat /tmp/freq.txt # View detailed chip status bitmain-soc --chips 2> /dev/null The miner log contains application-level messages including pool connections, chip enumeration, and hashrate data.
Before checking logs, the LED on the front panel provides an immediate visual indicator:
LED State Meaning Action Solid Green Normal operation No action needed Blinking Green Booting / initializing Wait 3–5 minutes for boot to complete Solid Red Critical error — miner stopped Check web UI and kernel log for specific error Blinking Red Fault detected — miner attempting recovery Check logs; may resolve on its own Alternating Red/Green Firmware update in progress Do NOT power off — wait for completion Red, then Off Boot failure or PSU issue Check PSU, try reflashing firmware No LED No power reaching control board Check PSU output, power cable, fuse Rapid Red Blink (5Hz+) IP conflict or network error Check network configuration
Never power off a miner showing alternating Red/Green (firmware update). Interrupting a firmware flash can brick the control board, requiring SD card recovery.
These errors relate to hashboard detection, communication, and ASIC chip enumeration.
Message Chain [X]: find 0 ASICSeverity Critical Meaning The control board cannot detect any ASIC chips on hashboard X Common Causes Loose data connector, broken CLK/CI signal trace, failed first chip in chain, EEPROM failure, PIC failure Quick Fix Reseat the hashboard connector. Swap the board to a different slot to determine if the board or the slot is faulty. Detailed Guide Hashboard Not Detected
Message Chain [X]: find 0 pcb or Chain [X] not foundSeverity Critical Meaning The entire hashboard is not recognized by the control board Common Causes No hashboard installed in that slot, completely loose connector, EEPROM unreadable, PIC not responding, cable fault Quick Fix Verify the board is physically installed. Reseat connector. Try a different cable. Detailed Guide Hashboard Not Detected
Message Chain [X]: find [Y] ASIC (where Y is less than expected)Severity Warning to High Meaning Some but not all chips on the board are detected Common Causes Failed chip breaking the daisy chain, broken signal trace mid-chain, cold solder joint, voltage domain failure Quick Fix Check ASIC status page — chips show as "o" (OK) or "x" (missing). Identify the position of the first missing chip. Detailed Guide Missing Chips Troubleshooting
Message Chip bin error or chip_bin mismatchSeverity Warning Meaning The chip hardware revision does not match what the firmware expects Common Causes Wrong firmware version for the hardware revision, replacement chip with different bin/revision, EEPROM data mismatch Quick Fix Verify you are running the correct firmware for your specific model and hardware revision. Reflash the correct firmware version.
Message Chain [X]: incomplete or chain init failSeverity High Meaning The chip chain initialization did not complete — some chips responded but the full chain could not be established Common Causes A chip in the middle of the chain is unresponsive, signal integrity issue (noisy CLK line), voltage domain not powering up Quick Fix Power cycle the miner. If persistent, check for voltage domain failures and signal trace integrity.
Message BO signal error or BO timeoutSeverity High Meaning The chip output signal (Busy Out) is not responding as expected during chip addressing Common Causes Failed chip, damaged BO trace, timing issue from noisy signal path Quick Fix Identify the chip position from the log. Inspect the BO trace for damage. May require chip replacement.
Message Temp too high or over max tempSeverity Critical (causes shutdown) Meaning Chip temperature has exceeded the maximum safe threshold (typically 85–95°C) Common Causes Insufficient cooling (dust, failed fan, high ambient temp), degraded thermal paste, blocked airflow, overclocking Quick Fix Power off immediately. Clean heatsinks, check all fans, verify airflow path is clear. Detailed Guide High Temperature Troubleshooting
Message temp sensor read fail or invalid temp readingSeverity High Meaning The temperature sensor on the hashboard returned an invalid reading or did not respond Common Causes Failed temperature sensor IC (LM75, TMP451, or NCT218), broken I2C trace to sensor, sensor desoldered Quick Fix If all other temperatures are normal and the miner is otherwise functioning, the sensor itself may have failed. Replace the sensor IC.
Message Hashboard overheat or PCB temp too highSeverity Critical Meaning The PCB-level temperature sensor (separate from chip temperature) is reporting excessive heat Common Causes A component on the board is drawing excessive current (shorted chip, failed regulator), or the board-level sensor is near a hot spot with inadequate cooling Quick Fix Check for hot spots with thermal camera or by touch (carefully). Look for damaged voltage regulators or shorted chips.
Message Temp too low or temp below thresholdSeverity Warning Meaning The reported temperature is below the minimum expected (sometimes negative or 0°C readings) Common Causes Faulty temperature sensor, broken sensor wiring, environment genuinely too cold for operation (below 0°C) Quick Fix If the environment is not extremely cold, the sensor has likely failed. Check sensor connections and replace if needed.
Message Fan speed error or fan [X] speed too lowSeverity High Meaning A fan is not reaching the expected RPM Common Causes Fan motor failing, fan cable loose or damaged, fan blocked by debris, bearing worn out Quick Fix Check that all fans are spinning. Reseat fan connectors. Replace the failed fan. Detailed Guide Fan Error Troubleshooting
Message Fan [X] not detected or fan lostSeverity Critical (most firmware will shut down) Meaning The fan tachometer signal is not being received — the miner thinks the fan is not present Common Causes Fan disconnected, fan cable damaged, fan motor completely failed, control board fan header fault Quick Fix Verify fan is plugged in. Try swapping fans between headers to isolate fan vs. header issue.
Message Fan speed abnormal or fan [X] RPM above maxSeverity Warning Meaning The fan is reporting an RPM higher than physically possible — usually a signal issue, not an actual speed problem Common Causes Electrical noise on the tachometer line, loose connector creating intermittent contact, wrong fan model with different pulse count Quick Fix Reseat the fan connector. If using a replacement fan, verify it has the correct number of tachometer pulses per revolution for the miner model.
Message Power supply fault or PSU errorSeverity Critical Meaning The PSU has reported a fault condition or the miner detected a power anomaly Common Causes PSU overcurrent/overtemperature protection tripped, PSU capacitor degradation, input voltage too low/high, hashboard short causing PSU overload Quick Fix Check PSU output voltage. Try with fewer hashboards to reduce load. Test with a different PSU. Detailed Guide Power Issues Troubleshooting
Message Voltage error or Vol Err chain [X]Severity High Meaning A voltage domain on the hashboard is reading outside acceptable range Common Causes Failed buck converter, shorted ASIC chip, damaged power trace, PSU voltage droop, corroded connector Quick Fix Check PSU output voltage. Inspect the hashboard for visible damage. Measure voltage domains. Detailed Guide Abnormal Chip Voltage
Message undervolt or voltage too lowSeverity Warning Meaning One or more voltage domains are below the expected voltage, but not critically failed Common Causes PSU aging, high ambient temperature reducing PSU efficiency, corroded power connector, early-stage regulator degradation Quick Fix Check PSU output under load. Clean power connectors. If PSU is aged (2+ years), consider replacement.
Message overvolt or voltage too highSeverity Critical Meaning A voltage domain is reading above the safe maximum — chips may be damaged Common Causes Voltage regulator feedback resistor open, regulator running uncontrolled Quick Fix Shut down immediately. Overvoltage can permanently destroy ASIC chips within seconds. The voltage regulator circuit must be repaired before the board is powered again.
Message pool connect fail or network errorSeverity Warning (miner continues attempting reconnection) Meaning The miner cannot reach the configured mining pool Common Causes Incorrect pool URL, DNS failure, network cable disconnected, router/switch issue, pool server down Quick Fix Verify pool URL and port. Check Ethernet cable. Ping the miner from another device. Try backup pool. Detailed Guide Network Problems Troubleshooting
Message IP conflict detected or rapid LED blinkingSeverity Warning Meaning Another device on the network has the same IP address Common Causes Static IP assignment conflict, DHCP server assigning duplicate IPs, or a second miner was cloned with the same configuration Quick Fix Use DHCP instead of static IP, or assign a unique static IP. Reset network settings via the physical reset button.
Message DNS resolve failed or hostname not foundSeverity Warning Meaning The miner cannot resolve the pool hostname to an IP address Common Causes DNS server unreachable, incorrect DNS settings, ISP DNS issues Quick Fix Configure a reliable DNS server (e.g., 8.8.8.8 or 1.1.1.1). Or use the pool's IP address directly instead of hostname.
Message firmware checksum error or image verify failSeverity Critical Meaning The firmware image in NAND flash has become corrupt Common Causes Power loss during firmware update, NAND flash wear, bad firmware download Quick Fix Reflash firmware using the SD card recovery method. Download the firmware file again (the original download may have been corrupt).
Message NAND read error or UBI errorSeverity Critical Meaning The NAND flash storage on the control board is failing Common Causes NAND flash has reached end of life (finite write cycles), physical damage, manufacturing defect Quick Fix Reflash firmware to remap bad blocks. If errors persist, the NAND chip may need replacement (control board repair).
Message config read error or config corrupt, using defaultsSeverity Warning Meaning The miner's configuration file is corrupt and defaults are being used Common Causes Power loss during config write, NAND degradation, firmware bug Quick Fix Reconfigure the miner through the web UI (pool URLs, worker name, etc.). The miner will create a new config file.
Message PIC error or PIC read fail chain [X]Severity Critical Meaning The control board cannot communicate with the PIC microcontroller on the hashboard Common Causes PIC chip failure, I2C bus fault (broken trace, failed pull-up resistor), EEPROM failure preventing PIC initialization Quick Fix Try reseating the hashboard connector. If persistent, the PIC chip may need replacement — this requires a pre-programmed replacement and soldering equipment. Detailed Guide PIC Microcontrollers
Message EEPROM error or EEPROM read failSeverity Critical Meaning The EEPROM on the hashboard cannot be read Common Causes EEPROM chip failure, I2C bus short or open, data corruption, connector issue affecting I2C lines Quick Fix Reseat connector (I2C lines pass through the connector). If persistent, the EEPROM chip needs replacement and reprogramming. Detailed Guide EEPROM Chips
Message EEPROM data mismatch or board info invalidSeverity High Meaning The EEPROM data does not match what the firmware expects for this model Common Causes EEPROM was programmed with data from a different model, partial data corruption, board was previously used in a different miner model Quick Fix Reprogram the EEPROM with the correct data for the specific board model and revision.
Message watchdog reset or wdt timeoutSeverity High Meaning The firmware hung and the hardware watchdog timer forced a reboot Common Causes Firmware bug, memory leak, corrupted firmware, control board hardware issue Quick Fix Check if the issue is consistent. Try a different firmware version. If persistent across firmware versions, suspect control board hardware. Detailed Guide Frequent Restarts
Message out of memory or malloc failSeverity Critical Meaning The control board has run out of RAM Common Causes Memory leak in firmware, too many concurrent operations, firmware bug Quick Fix Reboot the miner. If recurrent, try a different firmware version. Factory reset to clear any accumulated state.
Message CRC error or data integrity check failedSeverity Warning Meaning Data corruption detected during chip-to-control-board communication Common Causes Signal integrity issue (noisy environment, damaged trace), electromagnetic interference, degraded chip I/O Quick Fix If occasional, may be acceptable (firmware retries). If frequent, check signal traces and shield from EMI sources.
Message CLK error or PLL lock failSeverity High Meaning A chip's internal PLL (Phase-Locked Loop) cannot lock to the target frequency Common Causes Chip degradation, excessive overclocking, voltage too low for target frequency, damaged clock trace Quick Fix Reduce operating frequency. If the error is on one specific chip, it may need replacement.
Message hash test fail or chip [X] test failSeverity High Meaning A chip failed the built-in self-test during initialization Common Causes Degraded chip, voltage issue affecting that chip's domain, thermal damage Quick Fix Check the voltage domain for the failing chip. If voltage is correct, the chip is likely degraded and may need replacement.
Message freq set fail or frequency out of rangeSeverity Warning Meaning The firmware could not set the requested operating frequency on one or more chips Common Causes Requested frequency exceeds chip capability, voltage too low to support frequency, chip PLL issue Quick Fix Use the default frequency for your model. If custom overclocking, reduce the target frequency.
Message I2C error or I2C bus timeoutSeverity High Meaning The I2C communication bus has a fault Common Causes Shorted I2C line (SDA or SCL), missing pull-up resistor, damaged connector pin carrying I2C signals, component on the bus holding the line low Quick Fix Reseat connectors. Check I2C pull-up resistors (typically 4.7K to 3.3V). Measure SDA and SCL lines — they should idle high (3.3V).
Error Severity Category Most Likely Cause First Action Chain find 0 ASIC Critical Chain Connector / first chip Reseat connector Chain not detected Critical Chain Connector / EEPROM Reseat, swap slots Missing ASICs (partial) High Chain Failed chip in chain Check ASIC status map Chip bin error Warning Chain Wrong firmware Reflash firmware BO signal error High Chain Failed chip Check chip at error position Temp too high Critical Temp Cooling insufficient Clean, check fans Temp sensor read error High Temp Failed sensor IC Replace sensor Hashboard overheat Critical Temp Component fault or cooling Thermal camera inspection Fan speed error High Fan Fan motor failing Replace fan Fan not detected Critical Fan Fan disconnected Reseat fan connector Power supply fault Critical Power PSU overload/failure Test PSU output Voltage error High Power Buck converter / short Measure domain voltages Network error Warning Network Cable / config Check cable and pool URL Firmware checksum error Critical Firmware Corrupt flash SD card reflash NAND flash error Critical Firmware Flash wear-out Reflash, may need board PIC error Critical PIC PIC chip failure Reseat, then replace PIC EEPROM error Critical EEPROM EEPROM chip failure Reseat, then replace EEPROM Watchdog reset High System Firmware hang Try different firmware CRC error Warning Signal Trace damage / EMI Check signal traces CLK / PLL error High Chip Chip degradation Reduce frequency Hash test fail High Chip Degraded chip Check voltage, replace chip I2C bus error High Bus Wiring / pull-ups Check I2C lines
EEPROM reprogramming : If you do not have the correct EEPROM data for your board model, a professional with a library of known-good dumps can helpPIC replacement : Requires a pre-programmed PIC chip specific to your board model — professionals typically stock theseNAND flash replacement : Requires BGA rework equipment and a programmed NAND chipMultiple simultaneous errors : If you see errors across multiple categories simultaneously, a professional can more efficiently diagnose the root causePersistent errors after replacing obvious components : May indicate a subtle PCB-level issue requiring schematic analysis
Hold the reset button (small hole on the front panel) for 10 seconds while the miner is powered on. The LED will flash and the miner will reboot with default settings. You will need to reconfigure pool URLs and network settings.
Some warnings are informational and do not affect mining (e.g., occasional CRC errors). However, warnings often escalate to critical errors over time. If a warning persists across multiple reboots, investigate it before it becomes a critical failure.
Check the full kernel log for additional context around the error. Search the error message text online — Bitmain support forums, BitcoinTalk, and Reddit r/BitcoinMining often have discussions about uncommon errors. If the error contains a number, it may be a model-specific code not covered here.
Yes. Third-party firmware (Braiins OS, VNish, LuxOS) uses different error messages than stock Bitmain firmware. The underlying hardware faults are the same, but the log messages may be worded differently. This guide covers stock Bitmain firmware messages; consult the third-party firmware documentation for their specific messages.