Hoover HCA394FKPW Fridge Freezer, display flashing?

I have a HCA394FKPW fridge freezer. The display flashes on / off all the time. If I try to set the temp using the MENU button, it doesn't do anything for up to a minute. The screen misses the "Fridge / Freezer" settings but goes to the next setting. The screen then stays on as normal. I can then scroll through all the other screens as normal until I get to the start. The screen goes dead then starts flashing on / off again. The fridge is freezing the food, the freezer is fine. Any ideas please?