Analysis and Troubleshooting For Antminer 7 Common Error Codes

Compatible Models: Antminer L9, S21, S21 Pro+, S21XP, S19k Pro, S19, S19j Pro, L7 and other mainstream miners.

Target Audience: Mining farm operators, personal repair technicians, hardware maintenance engineers

Antminer is one of the most popular and frequently used hardware devices. However, long term high load operation can inevitably lead to various anomalies, resulting in hashrate drops or even shutdowns. This article systematically organizes the 7 most common error codes found in the Antminer kernel log, including error names, root causes, and step-by-step solutions. Following this guide, you can locate the fault and attempt a repair within 5 minutes.

I. Quick Reference Table of 7 Common Error Codes

II. Detailed Explanation and Repair Steps for the 7 Errors

1. ERROR_FAN_LOST
Definition: The system cannot detect the fan speed feedback signal at the corresponding position.
Common causes: Loose fan cable, fan jam or motor damage, faulty fan interface on the control board.
Solutions:
(1) Power off, then reconnect the fan cable, making sure the clips are securely locked.
(2) Power on and test. If the fan still does not spin, replace it with a fan of the same specifications.
(3) If the error persists after replacing the fan, the control board interface may be damaged; repair or replace the control board.
💡Tip: During routine maintenance, regularly clean dust from fans and keep a few spare fans of the same model as replacements.

2. ERROR_POWER_LOST
Definition: Communication between the power supply and the control board is interrupted, causing abnormal output voltage or complete loss of power.
Common causes: Poor contact of the power control cable, outdated or misconfigured power supply firmware, and aging power supply hardware.
Solutions:
(1) Reconnect the power control cable (usually a 4 pin flat cable), ensuring both ends are tight.
(2) Enter the backend management interface, then factory reset, then upgrade to the latest official firmware.
(3) If the above steps are ineffective, use a multimeter to measure whether the power output is normal (for example, 15V). If not, replace the power supply directly.
⚠️Note: When replacing the power supply, be sure to choose a model with a matching power rating and a reliable brand to avoid damaging the hashboard due to an unstable power supply.

3. Read temp sensor failed
Definition: The temperature sensor cannot return valid temperature data, which may lead to a protective shutdown.
Common causes: High ambient temperature, scale buildup on the water cooling plate, insufficient power of the water cooling radiator, cured thermal paste on the hash board, cold solder joint, or damage to the temperature sensor.
Solutions:
(1) Check the miner's working environment, ensure it is around 5 to 30℃, and improve cooling in the mining farm.
(2) Replace the water cooling plate.
(3) Check the radiator power, or replace it with a higher power radiator.
(4) Replace the thermal paste on the hash board.
(5) Replace the temperature sensor.

4. WARN_NET_LOST / NET Err
Definition: The miner cannot connect to the network or frequently disconnects, affecting hashrate submission to the mining pool.
Common causes: Damaged network cable or RJ45 connector, faulty switch or router port, IP address conflict, damaged network card hardware.
Solutions:
(1) Change the network interface: try a different switch port or connect directly to the router for testing.
(2) Check physical connectivity: use a cable tester or replace it with a known working network cable.
(3) In the backend, set a static IP or re-enable DHCP, and verify the gateway and DNS are correct.
(4) If packet loss persists and external network issues are ruled out, the control board's network card may be damaged; replace the control board.
📡Tip: For large scale mining farms, consider using an independent subnet and redundant switches to reduce single points of network failure.

5. ERROR_SOC_INIT
Definition: The main control chip (SoC) cannot complete initialization, causing the miner to hang on the boot screen or reboot endlessly.
Common causes: Poor contact of the control board cable, corrupted firmware, configuration conflicts in pool or chain settings.
Solutions:
(1) Power off, then reconnect the cable between the control board and the hashboard.
(2) Flash firmware via TF card: download the latest official firmware, use a TF card to force flash (note the file name must meet flashing requirements).
(3) After successful flashing, reconfigure the worker name and pool address in the backend, and disable unused chain options.
(4) If still failing, replace the control board for testing.

6. ERROR_EEPROM_INFO
Definition: The EEPROM data storing hardware parameters (serial number, calibration values, chain information) are corrupted or read incorrectly.
Common causes: Unexpected power loss during firmware upgrade, aging or cold solder joint on the EEPROM chip, chain configuration inconsistent with actual hardware.
Solutions:
(1) Re-flash the firmware via TF card: TF card flashing can rebuild the correct EEPROM data.
(2) In the backend under Miner Configuration, confirm that the set number of chains matches the actual number of hashboards.
(3) If repeated flashing is ineffective, the unit needs repair to replace the EEPROM chip on the control board or hashboard.

7. ERROR_ASIC_LOSS
Definition: The miner detects that some or all ASIC chips on a certain chain cannot be recognized, directly causing a hashrate drop.
Common causes: Insufficient power supply to the hashboard, open circuit in chip to chip communication, firmware mismatch with chip model, physical damage to one or more ASIC chips.
Solutions:
(1) First try restarting the miner and observe if the chips return.
(2) Flash the standard firmware via TF card.
(3) Lower the core frequency (for example, from 550M to 450M). If the chips reappear, improve cooling or replace the power supply.
(4) If underclocking does not work, hardware damage is basically determined; repair or replace the corresponding hashboard.
🔧Professional tip: Check the log entry Chain X ASIC number to identify exactly which chain has missing chips, allowing precise replacement of the hashboard.

III. Preventive Maintenance Recommendations (to reduce error probability)

Weekly: Clean the air intake filter, check if fan speeds are stable.
Monthly: Log into the backend to view logs and upgrade to stable firmware versions.
Quarterly: Use a thermal imager to check the temperature distribution of power supplies and hashboards, and identify abnormal hot spots in advance.
Environmental control: Keep mining farm temperature at or below 30, humidity 30%-70%, and avoid static electricity and dust accumulation.

IV. Frequently Asked Questions (FAQ)

Question: Can the miner still mine when reporting ERROR_ASIC_LOSS?
Answer: Yes, but the hashrate will drop significantly. It is recommended to follow the steps in this article as soon as possible; prolonged operation may damage the hashboard.

Question: What files are needed for TF card flashing?
Answer: Download the corresponding .tar.gz or .bin firmware for your model from official or reliable sources, place it in the root directory of a TF card formatted as FAT32, and usually rename the file to update.tar.gz.

Question: What to do if ERROR_POWER_LOST still appears after replacing the power supply?
Answer: Check if the power control cable is fully compatible with the control board. If confirmed correct, the fault may lie in the control board.

Question: If multiple errors appear at the same time, which one should be handled first?
Answer: Prioritize ERROR_POWER_LOST and ERROR_FAN_LOST, as these affect all hardware components; then handle network and ASIC chip loss.

When performing any hardware connection or disconnection and firmware flashing, always disconnect power first and back up data.

The 7 error codes listed in this article cover core modules, including fans, power supply, temperature, network, initialization, EEPROM, and ASIC chips, representing the most frequent issues encountered in field maintenance. For a more complete list of error codes, please click the link below:
Antminer Error Code Complete Guide

Of course, if you encounter a fault that cannot be resolved, please contact our technical team for support.