I'm posting this question for an elderly couple. They have a Tappan under the cabinet microwave that was made in 1992. After opening the oven, it keeps running. When the door is shut and opened again, it usually stops. I don't want this to be a dangerous situation for them. Is it worth fixing or should they invest in a new microwave.Thank you.

Microwave Ovens - Westinghouse - WST3501 Microwave Oven