A:
I don't see anything in the instructions about how to change the bulb. There doesn't appear to be a way to change it from the inside. i think you should call Sharp at 1800-237-4277 and ask them.
On a new unit the light should work but honestly, if I want to see what is going on in there I just open the door. I never replaced the light in my last microwave after it stopped working and I never missed it.