GE wall double oven (top oven with digital selections) cuts off mid-preheating or cooking (occasionally, 25% of the time). No codes are displayed, it just cuts off with no warning. Occasionally, it cuts off and once we see it, notice that the display reads "locked" as if it's in cleaning mode (50% of the time). Repeatedly pressing the "clear/off" button will unlock the door and allow it to be opened. Years ago, for a similar occurrence, I was advised to simply clean the connections on the motherboard (would need the directions to do this again though) and it would solve the issue. It seemed to until now. Any additional suggestions or could someone suggest how to again clean the connections if that's the best fix option? Any help would be appreciated!