This model has a safety feature that blows a thermal fuse if the cooling fan is unable to get a good enough airflow. When the fuse blows, it doesn't kill the oven completely but it does kill power to the programmer to alert you to the problem.
It could be caused by a faulty fan or by blocking the airflow. You MUST have a clear ventilation slot under the front of the oven.
To fix it, you will probably need a new fan board. Part No. 286613900
Barnaby
February 2010