Timothy A Frederick , CO May 08, 2020 Appliance: LG Microwave Hood Combo LMV1813ST/00 Lg Microwave Lmv1813st/00: No heat!. How to replace Microwave Door Switch. Two screws, remove input module. Behind, you will find the micro switches top and bottom. Pull connectors and change out switches. Replace input module. Do-It-Yourself Rating: Repair Time Estimate: Less than 15 minutes