Danger! You can receive a serious electrical shock from the components inside your microwave oven--even when it's unplugged. Only a qualified appliance repair technician should perform any repair.
Clean the inside of your microwave frequently. Food particles and splatters absorb some of the microwave energy while the unit is operating and may cause burns and other damage to the microwave. You can clean the interior with a microwave oven cleaner.
The touch pad controls, door hardware, and other exterior trim pieces last longer when they're clean. Here's a microwave oven cleaner you can use.
Because microwave ovens have solid state circuitry inside, they're susceptible to damage from voltage spikes caused by lightening, etc. We recommend that you plug your microwave into an appropriate surge suppressor to protect the circuitry.
Your microwave oven's door keeps the microwave energy inside, where it belongs. If the door is in any way damaged, or if the door seal doesn't seem to fit correctly or be in good repair, have the microwave checked by a qualified appliance repair technician.
Warning! Never operate a microwave oven without food or liquid inside it.
Microwave ovens heat by bombarding the food or liquid in the oven with super-high-frequency microwave sound energy. If there's no food or liquid in the oven to absorb the microwave energy, the energy can feed back to the microwave itself, which can permanently damage the internal microwave antenna (magnetron).