Kimberly R Parker , CO November 30, 2015 Appliance: Whirlpool Microwave MH7140XFB1 Whirlpool Microwave Mh7140xfb1: Grill broken on microwave. How to replace Microwave Vent Grille. I ordered a new grill on Tuesday before Thanksgiving and received it on Friday, day after Thanksgiving. It was shipped within hours of order. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes