I would appreciate info on my Bosch KGU3201GB/01 Fridge Freezer, which has the common fridge not cooling problem, but is an unusual configuration. Details below.

Ok, I have the common problem with Fridge freezers, the fridge is not cooling but the freezer is fine. I have a Bosch KGU3201GB/01 and this problem started yesterday. I have checked that the fan runs and took of the cover at the back of the freezer to find virtually no frosting. I defrosted it and left overnight with temperature monitors in both compartments. The fridge monitor went down to 3C in about 2.5 hours but then slowly warmed up again, reaching +8C this morning. The freezer monitor reached -12C after 2.5 hours and then continued to cool to -18C. I understand the principles of frost-free coolers but I'm puzzled by the details here and would appreciate some insights. Firstly, how does the fan blow cold air into the fridge compartment? Is there a duct up the back that I can't see without taking out the fan? What are the two cage-like structures on the left-hand side of both compartments? Do they house sensors? If so how do you access them? Any thoughts on the problem? One more question, where is the damper control? Re the answers to date, see the extra info, I have checked the fan and defrosted already. Further update: I just noticed that the fridge compartment is now at 2C. This model doesn't have any obvious air channels inside, so I checked with a thermal imaging camera and the whole back wall is at 2C, so the air circulation duct must be inside the back wall?? Further update. Ahh, this model doesn't have air ducts, there is a separate cooling line from the condenser running into the back wall of the fridge compartment. I managed to get a flow there by toggling to Super and then back to Eco. The thermal imaging camera shows the back wall cooling to -24C. Unfortunately, I don't think this will last. Does anyone have experience of this model, to suggest what's wrong??