Richard G Lincoln , NE March 07, 2018 Appliance: Whirlpool Microwave Oven 1.5 Cubic Foot MT4155SPT1 Whirlpool Microwave Mt4155spt1: Door would not open. How to replace Spring, Release Button. Replaced door latch bracket. We wanted to keep our bisque colored microwave. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes