Fix Fans and AIO Not Spinning After a Fan Hub Replacement

Introduction

If your PC fans, including the AIO, are not spinning after replacing the fan hub, this guide will help you check the most common causes and identify the next best step. Fan hub replacement issues are often caused by a loose connection, incorrect installation, or a faulty replacement part.

Issue description

This issue occurs when one or more case fans, radiator fans, or the AIO fan set do not power on after a fan hub has been replaced. In many cases, the system may still boot normally, but the fans remain stationary or do not respond to temperature changes.

Signs

• Case fans do not spin at startup
• AIO radiator fans do not spin
• RGB lighting may still work while fan blades remain still
• Fans do not respond to BIOS fan curves or software control
• The issue started immediately after the fan hub replacement

Basic troubleshooting steps

Before assuming the new fan hub is defective, check the following items carefully.

• Confirm the fan hub is installed in the correct orientation and location
• Make sure the hub has proper power from SATA, Molex, or the required power connector
• Verify the motherboard PWM or fan control cable is connected to the correct header
• Check that each fan is fully seated in the hub ports
• Inspect the AIO pump and radiator fan connections separately, if applicable
• Look for bent pins, damaged cables, or loose adapters
• Power the system off, reconnect the cables, and test again

Advanced troubleshooting steps

Step 1: Test the fan hub connections one by one

Disconnect and reconnect the hub power cable, motherboard control cable, and fan leads one at a time. If possible, test each fan directly on a motherboard fan header to confirm whether the fan itself spins.

Step 2: Bypass the new fan hub

If the fans spin when connected directly to the motherboard, the replacement hub is likely the source of the problem. If the fans still do not spin, the issue may be related to the fan, AIO pump, motherboard header, or power delivery.

Step 3: Check BIOS fan settings

Enter the BIOS and confirm the fan header is enabled and set to the correct control mode, such as PWM or DC. If fan stop mode is enabled, disable it temporarily for testing.

Step 4: Inspect the AIO separately

If the AIO pump or radiator fans are not spinning, verify that the pump has dedicated power and that the AIO is connected according to the manufacturer’s instructions. Some AIOs require a separate pump header or SATA power connection.

Contact support

If the issue persists after confirming the hub installation and cable connections, the new fan hub may be defective or another component may be preventing the fans from spinning. Please contact CLX support for further assistance so we can help diagnose the issue and determine the next step.

Additional information

When contacting support, please have your system model, fan hub replacement details, and a description of the connections you tested available. This information helps speed up troubleshooting and warranty or repair coordination if needed.

Disclaimer

Follow all hardware troubleshooting steps with the system powered off and unplugged unless instructed otherwise. If you are not comfortable working inside your PC, contact support for help before making additional changes.