Rangemaster six’s fridge freezer

Can anybody help, I have a Rangemaster sxs fridge freeze, model number I believe U109200-03, we have had it from new, I think about 10 years now, problem is the freezer is working fine but the fridge isn’t the temperature control on the frount is not a light, and hence can not be set, every thing else as I say is fine,is it a simple fix, or should I need to call someone out, any help will be great fully appreciated.

Thanks Gary