Samsung Model MR6699GB microwave, unit comes on but does not cook

Its either your primary door switch or there is a diod inside on the right rear that needs to be replaced. to check the door switch, remove the cover disconnect the wires frome the switch and place a jumper wire on them and try it . if the problem persists it the diod. be carful. make sure there is no power going to it when your hands are in the microwave. and do not let it run to long or you will damage it.