My Jenn-Air Microwave (Model Number : jmv8208bas) is sparking and its coming from top circular cover I tried to remove it to check if I could spot any damage but the cover won't come out (instruction says to turn to remove). Should I try to un-install the microwave and try to diagnose. What could be the problem and is it repairable ?

Microwave Ovens - Jenn-Air