When BAKE is selected and the temperature set at say 550 F, the flat plate white base igniter heats up (draws 3.65-3.7 amps) and the voltage at the safety valve reads 4.1 VAC (valve label reads 3.33 VAC). The burner comes on and the temp on the readout races up to the set temp in about 20 seconds and then thinks it is at the set temp and shuts off the burner. However the temp in the oven is nowhere near 550 F, more like 200 F. After about 60 seconds this cycle repeats but gets shorter each time as the oven heats up little by little. Is the problem the oven temperature sensor or the clock / control panel which is no longer available?