How do I convince her

My wife stops the microwave by opening the door before it's finished and leaves the time left on the display. It's mildly annoying. I'm trying to come up with a reason to tell her that will make her stop. (All in fun.)

My current (I've been in software development for 30 years) "explanation" is that there is a software program running to update the clock. Every minute it tries to update the clock on the screen and throws an exception (make this sound as serious as possible) because she left the remaining time displayed. This can, over time, degrade the circuitry. She doesn't believe me.

Help me come up with a believable story.