If you are experiencing issues with your Grid+V3 and your fans are not spinning, we recommend you check the specifications on the fans. The Grid+V3 supports up to five watts (5W) of power draw per channel. If a fan were to exceed this threshold then it would trigger the fail-safe the Grid has and shut off all fans.
If you do find that a fan you are using does exceed the limit then you would need to disconnect that fan from the Grid+V3. To do so, first power down your system fully and turn off your power supply. Wait 10 seconds and then remove the fan, then turn on your system and the fans should spin.
If you need assistance with additional troubleshooting or have any further questions, please contact our Customer Support Team.