Display and oven not operating

When we returned from vacation, the display on our Maytag range was dead. The burners and oven light operate OK but the panel will not light and the controls won’t operate. A serviceman came and wanted to replace the main circuit board at a cost in excess of $400. My questions, where is this circuit board located, how is it accessed, what is the part number, and how much does this part cost? I was at work when the service man was here and did not see what he did.

I am trying to make a determination if I can repair this problem myself (I am an engineer and familiar with wiring and electronics) or if I should just buy a new range. That answer will depend on the cost to make this repair.

Thank you for your response