Flashpointmo for Model Number Tappan My Tappan over the range microwave that I had for 18 years, makes a loud humming noise and does not heat anything up. Could it be a diode?
Answer Hello flashpointmo. You need to check the magnetron and diode in the unit. Look for cracked magnets and make sure the magnetron reads less then 1 ohm. Also, the diode should only read 1 direction. You can test this with a multi-meter TJMA-DMT3. Here is a link on how to use a multi-meter. http://forum.appliancepartspros.com/oven-repair-including-ranges-cooktops/4810-how-check-continuity-ohmmeter.html Read More... Answered by AppliancePartsPros.com | Thursday, March 14, 2013