Phil B Lexington , KY November 07, 2022 Appliance: Whirlpool Microwave WMH73521CE0 Whirlpool Microwave Wmh73521ce0: Door open/close fault. How to replace Cam-Plate. Replaced the switch and while at it replaced the cams to be sure switches stayed in perfect sync. Do-It-Yourself Rating: Repair Time Estimate: 30-60 minutes