Range Membrane Switch or Control Board?

We have a NX583G0VBW/AA free-standing gas range. About two months ago, it began repeatedly beeping and displaying the error code of SE, leaving the burners working, but not the oven. The touchpad, which we believe is called a range membrane switch, would not work. We have repeatedly tried unplugging the stove and even resetting the electrical breakers on our outdoor box. Sometimes when we unplug and then plug in the cord again, the touchpad will flash all the oven functions and when it does so, the touchpad and oven temporarily work again. One time, the touchpad and oven worked again for about five days without any problems, but then it began beeping and reset to the all-too familiar SE error code.

Is there a way without fancy tools to determine whether this is a range membrane switch or a control board issue? We are seniors, so we don't have a large budget.

Thank you very much.