I have an Inspiron 4100 and it has been getting very warm on the bottom.  I talked with technical support to see if this was due to the very warm weather or if there was a problem.  I explained to them that I never hear the fan.  They couldn't help me with the diagnostic so they told me I just needed to have fan replaced.  Since then, I was able to run the diagnostic and the fan tests passed.  I blew compressed air into the fan vents as well.  Should I have the fan replaced or should I continue to use it as is?  If I should have the fan replaced, is it a job where you can follow the directions and do it yourself or should a repair person do that.  Is it possible to find Dell certified technicians?  How do you go about finding one?