Bad control unit?

The LED display on my Jenn Air range has not worked for years, but everything else had been working fine until the oven stopped working the other day. The fan, light, timer and stove top were still working. I checked the baking element and this was fine. However, one of the wires from the broiler element was missing. This was found and reattached by a repairman who confirmed that I needed a new control unit. It should be noted that after the wire was reattached to the broiler, the oven started beeping and the fan and light stopped working. I just replaced the control unit and nothing has improved except that now the LED display is dimly lit. Anyone have any suggestions?