Is it gas or electric? and have you checked the breaker? Electric is 240 v and sometimes half the breaker will trip allowing console to come on but yet not heat the oven........

I believe this unit has a user interface/touchpad and main control separate. The problem your stating since all the other buttons work is more then likely a user interface/touchpad issue. You can call some manufactures and get a pin test sequence on what buttons to press while doing a continuity test to see if the touchpad is functional. Before investing on the interface take into consideration also that some interfaces work with the main control even if it just seems like a button issue it can be a main board issue and have nothing to do with the interface i know it's odd but i've seen it a few times. Before buying a new interface take into consideration the cost of the touchpad and maybe the possible main board also. Take into consideration the age of the unit and it's worth before investing alot of money into these parts. Also there can be a wire harness issue with a short somewhere but that doesn't happen to often but it's possible.