Bosch HBM56B551B/45 double oven.

Bosch HBM56B551B/45 double oven. FD9206.

Display dead. No clock, controls, no selector…. no life at all. Top oven works fine; lower oven dead. Selector switch looks fine and switches cleanly; all selections for top oven are functional. The supply for the lower oven seems to route through a ceramic resistor – this is getting hot. There are three PCB’s: one is the control PCB (display) 657715; the square main module with several relays 657698 and a small mains power PCB 656768.
There is power to the main square PCB 657698. The display is supplied by a small loom to a plug on the main board. The small mains power PCB does what?
This is one of those chicken and egg jobs that really requires a bucket full of bits to randomly plug on and off ’till it works. 😉 Not having that luxury, can anyone shed some light on this fault please? The customer reported the display becoming dimmer over a period of time and the controls were difficult to operate – then dead.
I’m thinking display board but I have no way of testing that theory. All boards have been out, terminals cleaned, tightened and inspected for component failure / dry joints…. all OK.

Foxed…… or another word beginning with F. :angry4:

Help !!! Some tech or experience of this oven would be gratefully received!

Thanks!

Steve.