Notifications
Clear all

Failing Fan Calibration  

  RSS
Sailorbuoy
(@sailorbuoy)
Member
Failing Fan Calibration

My MK4S / MMU3 is failing the fan calibration test after doing a factory reset and installing the latest 6.4.0 firmware for MK4S. I installed a new Love Board thinking that was the problem. Checked the fan, it spins freely. I checked the connection and it was good. Then just to make sure it was not a broken fan, I swapped the connectors on the Love Board and the print fan worked but then the heatsink fan did not work. I checked the printer model in settings and it is MK4S. Any other ideas?

Napsal : 14/12/2025 2:34 am
LarGriff
(@largriff)
Reputable Member
RE: Failing Fan Calibration

Try reverting to 6.2.6.  LOTS of people have reported problems with 6.4.0 especially on the MK4S/MMU.

MK4S/MMU3

Napsal : 14/12/2025 3:18 pm
Share: