This unit bahaves as follows:

You can select a bake function and enter a temperature for the preheat. The element comes on and preheat commences, then the the bake program (that has been selected) disappears and the clock reverts to time of day and the oven shuts off. It's as though you had hit the cancel pad except there is no corresponding beep to denote entry of the cancel button.

After trying several times the oven may go ahead and heat normally or it may shut off during use. There are no beeps, as would be heard if the clear pad was shorting.