I'd pop a question in the microwave section if I was you. This is for PC s and Microwave people don't come here.
However my small amount of knowledge tells me that it is EXTREMELY dangerous to take the covers off a microwave if you do not know what you are doing. It can cause microwave leakage which is potentially lethal.
howtomendit.com for free repair help, information and advice.
Try fixfault.com to fix desktop pcs.