I have a Maytag Magic Chef 34JN-2CKX-ON gas stove. The oven stopped heating. There is a bottom burner and a top burner bar. When I turn the oven knob to temperature the bottom glow bar comes on and gets very hot. The top one does not come on. As I understand there are temp. sensors at the igniters that switch the gas on if hot enough. Should the bottom burners come on, or do both igniters need to come to temperature before any gas gets turned on? What would be the first troubleshooting steps? Check fuses and replace top glow bar?