Over the range microwave. 1st one purchased, bulb blue than the keypad wouldn't work. Bulb

Question

1st one purchased, bulb blue than the keypad wouldn't work. Bulb exploded when tried to remove. Couldn't get bulb out of socket. Returned for an exchange. 2nd one burnt wholes through center of frozen entrees. Damaged dishes. Exchanged for a 3rd one. Microwave shuts off if item gets too hot. Cook two bags of mini popcorn. 1 minute 20 seconds each. part way through the second bag, the microwave shuts down.