Fan Shutting Off After a While

Issue Overview

Users have reported that after starting the Nvidia Jetson Orin Nano Developer Kit, the fan’s PWM (Pulse Width Modulation) value is initially set to 128. However, within 1-2 minutes, this value begins to rise until it reaches 255, at which point the fan shuts off completely. This behavior occurs independently of the actual temperature readings from the board. The issue arises during normal operation, and it has been noted that the fan control is managed by the nvfancontrol service, which is expected to adjust fan speed based on temperature.

The configuration file for nvfancontrol indicates that the fan should decrease its PWM as temperature rises, but users have observed that this is not happening as intended. The problem has been consistently reported, affecting user experience by risking overheating or causing unnecessary noise and power consumption.

Possible Causes

• Hardware Incompatibilities or Defects: There may be issues with the fan hardware or connections that prevent proper operation.
• Software Bugs or Conflicts: Bugs in the nvfancontrol service or conflicts with other software could lead to improper fan control.
• Configuration Errors: Incorrect settings in the /etc/nvfancontrol.conf file might result in unexpected fan behavior.
• Driver Issues: Outdated or incompatible drivers could affect the communication between the system and fan control mechanisms.
• Environmental Factors: High ambient temperatures or inadequate power supply could influence fan performance.
• User Errors or Misconfigurations: Users may inadvertently misconfigure settings that impact fan control.

Troubleshooting Steps, Solutions & Fixes

1. Verify Hardware Connections: Ensure that all connections to the fan are secure and there are no physical defects.

2. Check Current Configuration:

   • Review the contents of /etc/nvfancontrol.conf for any misconfigurations.
   • Use the command:

     cat /etc/nvfancontrol.conf
     

3. Disable nvfancontrol Service:

   • Temporarily stop the service to determine if it is causing the issue:

     sudo systemctl stop nvfancontrol
     

   • Monitor if the fan continues to operate without shutting off.

4. Monitor PWM and Temperature:

   • Use a monitoring command to observe PWM and temperature changes:

     watch 'nvfancontrol -q; echo "temp: "; cat /sys/devices/virtual/thermal/thermal_zone*/temp; echo ""; echo "pwm"; cat /sys/class/hwmon/hwmon2/pwm1'
     

5. Modify Fan Configuration:

   • Adjust the PWM values in /etc/nvfancontrol.conf to see if different settings yield better results. For example, try changing values in the FAN_PROFILE sections.

6. Update Drivers and Firmware:

   • Ensure that all relevant drivers and firmware are up to date. Refer to NVIDIA’s documentation for updates specific to your JetPack version.

7. Test with Different JetPack Versions:

   • If possible, test with a different version of JetPack (e.g., L4T 35.4.1) to see if it resolves the issue.

8. Use Alternative Fan Control Methods:

   • Consider using other tools like jetson_clocks for manual fan control:

     sudo /usr/bin/jetson_clocks --fan
     

9. Capture Serial Console Logs:

   • If issues persist, capture logs during boot to identify any errors related to fan control:

     minicom -D /dev/ttyACM0 -8 -b 115200
     

10. Best Practices for Future Prevention:

    • Regularly check for software updates from NVIDIA.
    • Ensure proper cooling solutions are in place and monitor ambient temperatures.

By following these steps, users should be able to diagnose and potentially resolve issues related to their Jetson Orin Nano’s fan shutting off unexpectedly. If problems persist after attempting these solutions, further investigation may be required into hardware defects or deeper software issues.