Thank you for your question.
Microwaves are inherently dangerous to service. They contain high voltage internal components that can retain a lethal electrical charge even when the microwave is completely unplugged. A microwave shielding leakage test must be performed on the unit using proper testing equipment following any internal component access or repair before the microwave can safely be returned to service. These are the reasons why I recommend that you have a service technician repair this microwave failure.
The light bulb can only be accessed by taking the cabinet off. I do not recommend doing this.
The light bulb is a special type and the part number is:6912W3B002L and you can purchase this from
Sears Parts Direct
If you do not feel confident repairing this problem yourself, then you can have it repaired by a Sears technician. Here is a link that will provide the nearest drop-off locations:
Sears Home Services
I hope this will help.
Thank you for using Manage My Life.