Hotpoint DE89x/1 Fan not working

Hi. The main oven on my Hotpoint DE89X/1 (out of warranty) is heating up but the fan is not working. I replaced the fan but the problem remains. There is power getting to the fan. I cannot find a circuit diagram for this model. There is a clicking noise when opening/closing the main oven door, but somehow the message is not getting through to turn the fan on. Any ideas please? To replace the whole board is quite pricey and I want to be sure it will solve the problem. Thanks.