If nothing is coming up on the hob
when you turn it on other then the hob light for the split second then this is going to be either the mains connection unit or the control board here.
As in these hobs theres only the mains connection box, control board and the elements. Now for this it wont be the elements so it only leaves the connection box or the control board.
If fixing this yourself then you need to remove the hob from the work top and turn it over.
There you will see a cover were the power cable goes to. Open this and check the wiring connections and make sure theres no burning in there. If you have a multi meter you need to check theres 230v there.
If the power is fine and the mains connection is ok then this is going to be a faulty control board under the glass top at fault here.
To access this you need to remove the glass top and you can access it there at the front. You will need to replace that. But this isn't a cheap part. Its coming up at £310 direct from Bosch so for that price its probberly not even worth fixing here im afraid.
So check the above out if you can and see what you find.
If you need anymore info just get back to me.