How can I fix my Schott Ceran Hob?

When I turn my schott cewan hob on all the lights come on when I touch each sensor, I have power, numbers on each one goes from. 1 to 9 . On every ring, it is not locked. The problem is none of the 4 rings heat up , I've had it a year and no problems . I think it must be a sequence problem but I can't work it out ! Can anyone help please .

bob

Bob
January 2017