This is a 24-year old, 1.8 cu. ft Inglis microwave (manufactured in the U.S. by Sharp). It has a rotating element in the roof, a temperature probe and a metal rack. Lately, the microwave has been starting and stopping in the following manner: when you close the door, the display may blank out - if you are successful in getting the microwave going, it will sometimes stop (display goes dark), restart and then stop again (several times). Through trial and error, we have found that if we press the keypad at the left edge a couple of inches above the door push-button, it will often resume cooking. Once in awhile, we have to continue to hold our finger at this point until it is finished heating. Every time it quits heating, the clock also stops and it loses time. The push-button to open the door is not as 'smooth' as it once was and there are two 'tabs' on the inside of the door that seat into their respective 'tunnels'. I am pretty sure that there are some kind of interlocking switches at the end of at least one of these 'tunnels' and I suspect that this might be the source of the problem. There is also a prong that pushes a small 'door' just below the bottom 'tunnel' (I think it has a switch behind that controls the light in the oven) and that 'door' often sticks and the oven light goes out.
I think that it may just need the inter-lock switches lubricated or, worst case scenario, replaced, but I am having trouble getting the cover completely off the unit. There are two screws at the bottom of each side and four screws along the cover lip that folds around the back (1 for each side and two for the top). I am able to lever the cover up at the back by spreading the sides out but the cover is solidly connected at the top front. I have tried pushing the cover as close to straight forward as I can and straight back to no avail. I don't want to break it where it is attached at the front but I feel that I need to get it off to be able to see and work inside the unit behind the keypad and door lock switches. There are two removable panels on the bottom of the until which may allow some access to components in the lower part of the oven.
Any help/advice would be most appreciated. Thanx in advance.