Roy S Jacksonville , FL January 31, 2022 Appliance: Samsung Microwave Hood Combo ME18H704SFS/AA-0000 Samsung Microwave Me18h704sfs/Aa-0000 / : Samsung me18h704sfs over the range microwave would not heat. How to replace Microwave High Voltage Diode. Replaced the magnetron using replacement part OM75P-21-ESGN. And the microwave started heating food again. The most challenging part of the repair was taking out and putting back all of the screws in the cover. 3 People found this story helpful Do-It-Yourself Rating: Repair Time Estimate: 1-2 hours