Do not have all the details yet from my 86 year old father but do have a question. He said he only has oven temp of 350 or 375 so I'm assuming the control pad is not working properly. My question, how do I diagnose if the problem is going to be control pad or the control board (lol, I'm female and will attempt to fix myself) I'll get more detail later but thought if I had answer to this my dad could diagnose over the phone with me?