LG Microwave Error Code SE

SE stands for Key Short Error on an LG microwave. It means the control board detected a continuous key input signal lasting more than 10 seconds, which is outside normal operation. When this happens, the microwave displays SE and switches into cancel mode to prevent unintended cooking. The cause is usually a stuck button, a damaged keypad, or contamination under the control panel surface.

Start by turning the unit off and back on to clear the fault. Then inspect each button on the control panel for sticking, debris, or lack of normal spring-back response. Clean around the keypad surface to remove any grease or moisture. If the error returns immediately after restarting with no buttons pressed, the membrane keypad or control board likely needs to be replaced.

Repair costs vary depending on the root cause. Cleaning a contaminated keypad costs little to nothing beyond your time. A replacement membrane keypad part typically runs in the range of $20 to $60 depending on the model. If the control board is the source of the problem, parts alone can range from $50 to $150 or more, with professional labor adding to that total.

Turning the microwave off and restarting it will clear the SE display and cancel mode temporarily. However, if the underlying cause, such as a stuck key or shorted keypad, is still present, the error will return shortly after restart. A reset is useful as a first diagnostic step to see whether the fault is intermittent or persistent.

When the SE error is active, the microwave automatically converts to cancel mode, which means it stops normal operation on its own. The unit should not be used for cooking while the error is present, as the control system may not respond predictably. Resolve the underlying keypad or control issue before returning the microwave to regular use.