I have a Whirlpool Built-in double wall oven. Recently, the display went out. The ovens still worked but you could not tell what temp the units were set at. I purchased and replaced a control board for the oven. After replacing it the upper oven an display both work fine. The lower oven no longer works. The display for the lower oven works and it even shows that the oven is in "heat" mode but the oven does not heat up. I have reviewed the wiring and everything appears to be connected properly. Any ideas on what could be the issue? I appreciate any commments.