Cannot select program?

I have a Baumatic BDW15 dishwasher. When I switch it on all the control panel lights flash on and then off. But I cannot select any programs after that. None of the control panel lights are lit.
Originally the machine was showing and E4 error and the bottom of the dish washer was filled with water. I have removed the water and the E4 error has cleared but now none of the control panel lights come on, as described above.
I do not believe the control panel is faulty because if I switch the machine on and manually raise the overflow float the E4 error comes on, which suggests that that the control panel is functioning.