There is a speed feedback signal from the part cooling fan. Normally, when applied a voltage, the fan will perform a corresponding spinning speed, and the printer will check the feedback speed and see if the fan is working normally. If the feedback speed of the cooling fan is slower than designed, this error message will occur.
Below are the possible reasons:
If the fan is turned on, when cleaning the fan, the fan may start spinning suddenly and cause injury. So make sure the fan is turned off when starting the following step.
If Step 1 doesn't work, check whether the connector is loose.
Refer to the Wiki to check and reconnect the part cooling fan connector.
Then try turning on the cooling fan again.
If Step 2 still doesn’t work, the cooling fan might be damaged and needs to be replaced.
H2D - Replace Part Cooling Fan
We hope the detailed guide provided has been helpful and informative.
To ensure a safe and effective execution, if you have any concerns or questions about the process described in this article, we recommend submitting a Technical ticket regarding your issue. Please include a picture or video illustrating the problem, as well as any additional information related to your inquiry.