Oven shuts off

I have the same problem as JuJu (earlier post) "While baking, oven randomly just shuts down. All lights go out and heat goes off.Attemps to restart it fail but if the door is gently slammed shut it comes back on again. the 888 appears on the panel and the I reset the settings. This happens many times during the course of baking. Unable to keep the oven on for any length of time. No error message.