Under certain conditions, the 24V fuse on the Duet2 mainboard may be overloaded. You will know if fans don't turn on and the cleaning station does not operate. These are standard mini blade automotive fuses. The 24V line is in the location indicated below, and should be replaced by a 2A fuse (like this). If you are repeatedly blowing this fuse, you may increase the fuse rating to 3A, per this documentation.