Hi sir, Heat: like all electrical components, sources do not get along very well with high temperatures. If the inside of the case is not properly ventilated or the fan has failed, it could cause premature death of the component. Be careful if your equipment is below the guarantee contact Dell technical support If it is not the case do the following Check that it is connected and that the power cable is not damaged. Before moving on to the motor, disconnect it and check both the motor and the rest of its internal components. If there's nothing unusual, it's probably the thermal fuse. If you do not want to damage the motor, it is best to change it Greetings JenselPC.
PSU fan never turned on?
XPS 8930, PSU fan