Just recently i was using my microwave when i smell like a burning smell coming from it. So i removed what i was using out of it then try ed just operating it without anything inside however the problem was still there. Today i tried it out again to see if it needed time to cool down or whatever but it is no different and i have noticed that the heater bulb or whatever it is is glowing a really bright red colour. What is the problem and how do i solve it?