GE spacemaker xl1800. My son put his pop tart in the microwave with the foil still on and you know

Question

My son put his pop tart in the microwave with the foil still on and you know it smoked made noise etc. Now the microwave will not heat at all. All parts work turn table turns lights come on but no heat?? magnatron, board or voltage dohicky? I can check voltage and or test continuity if needed.....