Warm Bosch Fridge

Hello all,
i have a Bosch Exxcel frost free fridge/freezer 50/50 split with a falling cold air system – KGH33V63GB/03

As per many posts on this website – the fridge is not cooling and is around 12°C.
I have searched high and low over the internet to identify the problem but no such luck.

This is a list of the symptoms and what ive tried:
– The freezer compartment is working fine
– I have done a 48 hour deforst
– when i open the fridge door and press the door switch, the fan activates. However the other day i noticed the fan was not operating when i did this.
– coils on rear have been cleaned

I’m not 100{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} certain how the fan works but i believe there could be a “flap” where the air enters the fridge to control the temperature, could this “flap” be malfunctioning?
Could it be a thermistor?

can anybody help me???

Thank you.