Can you advise the model of hob you have?
Unfortunately this is a very common fault, the hobs dont appear to like being left without power. Ive seen two this year, already caused by power cuts etc, I think its due to a sudden surge when the appliance is turned back on.
The fault relates to a hardware fault on the power regulator and main board, if the appliance is under warranty its worth booking an engineer for free by calling***********and press option 2, otherwise if you provide me your post code I can recommend a service company in your area.
Based on experience the parts are likely to be expensive (around the £100 mark), however the error codes are rather generic so its hard to say you need this part and it will cost x, as it may just be a burnt out cable, but it could equally be the voltage regulator\stepper.
The two companies I would recommend are Marchwood (023 8098 2377) and Premier Electric (02380 582562), I havent been able to get hold of Marchwood to get a call out charge but think they are cheaper than the £70 Premier Electric charge, however Premier refund you the call out fee if you ask them to do the repair. Both companies we have used for repairs in the past and have always had excellent feedback.
So I may close the case can you please, rate the service received.