Both bake and broil won't light. Cooktop works fine. At first, it would light but not get to temperature, so I replaced bake sensor. Did nothing. Then it sometimes start, sometimes not. Then stopped fully. Checked gas valve resistance - all OK. So I replaced main control board. Worked once, but not again. I assume I need to replace DSI board, but i am tired of wasting money. Hoping to get expert guidance. Thanks!