We bought this new in 1993 and it does have an electronic control panel. The top unit works fine. When you turn on the lower oven and set it to a temperature, the element starts to heat up then it shuts off about a minute later. The display also shuts off, indicating the lower over was turned off by itself. I replaced the heating element and checked the connections and everything is fine there. Any suggestions what to do next? No error codes show up on the display.