The fan is located in the center of the tray, the fan draws in external air and blows internal air through the 4 directional vents. More information can be found in the maintenance section of the owner’s manual.
The fan/motor may have shifted (likely during transit). To remedy this, please remove the top cover, then remove the cover over the fan and inspect to see if the fan blades can turn freely. Once identified, replace both covers and test the unit.