firstly check that the power is on at the boiler electrical supply and that the fuse is ok otherwise it
may be a blown fuse on pcb, faulty main pcb, faulty user control pcb or faulty wiring harness between main pcb & user control pcb.
best to get a qualified engineer in to test it out as it could either be a very expensive repair if it's the main pcb or in the case of the wiring harness, pretty cheap.
Ian
July 2011