Why Is the Microwave Light on but the Microwave Does Not Work?

Jon Stefansson

Troubleshooting a microwave oven that lights up but doesn’t work involves ruling out some of the most common technical faults. By troubleshooting at home, you save time and money by fixing the appliance yourself.

Examine your microwave for problems.

Out-of-warranty visits by technicians are often expensive, especially if the problem turns out to be simple enough to fix at home. The most common problems that produce these symptoms are easy to fix without special tools or expertise.

Incorrect Programming

Re-enter your cooking instructions, making sure to cancel any time delays, entering a weight for the food, if necessary, and pressing the "Start" button when you are ready to begin. Skipping any of these stages may prevent the oven from starting. Always ensure the door is completely closed if the oven fails to start.

Child Lock Active

The child lock stops children from playing with the oven, changing settings and starting the appliance by themselves. The oven works normally, lighting up and reacting to input, without starting. Hold the button with a padlock icon for a few seconds to turn off the child lock.

Set the Clock

Some ovens will not start unless the clock is set. The setting might have been erased if the power was interrupted to the appliance. Follow the instructions outlined in the instruction manual to set the time and re-enter your cooking instructions.

Demo Mode Active

Some microwaves have a demo mode that shows off the appliance's features in the showroom without activating the magnetron, the part of the oven that generates heat. The controls light up, and the oven accepts input, but the timer often runs at double speed. Unplug the microwave, wait at least a minute and reconnect the power to cancel demo mode. You may have to hold a few buttons once the power comes back on to completely cancel demo mode -- check your manual.