Paul A Merrimack , NH April 07, 2017 Appliance: Samsung Microwave SMH7178STE/XAA The fan that cools the main unit had stopped running The fan that cools the main unit had started making noise a few weeks ago, I tried cleaning and lubricating the bearings, but the fan would make noise when it heated up, then finally stopped. I replaced the fan, it was up and running within 20 minutes of receiving the parts. Read More... 1 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 15-30 minutes Tools: Screwdrivers