whirlpool AKP203/IX dead except oven light

Hi. Got Whirlpool b/in single door oven ( version 857720315511 ) that is dead, except for the oven light comes on. There are two pcb`s 1 is a small power module and the other is the digital display pcb which is totally dead. Before everything went so horribly wrong the display was very subdued. Logic dictates that it`ll be the display board that`s u/s but not necessarily!! I`ve got power to the power pcb and visually it looks perfect, ah, but then so does the display pcb too. The dilemma of it all!
Anyone come across this before? Any pointers please? Thx.