Ariston MBA3842 c uk fridge not cooling freezer ok?

I have an Ariston MBA3842 c uk ffridge freezer. The one with the digital display on the door
The problem is the fridge is not cooling but the freezer is ok
It sounds ok, makes the noises it should & the fan in fridge turns.
I recently changed the door cable to the display as that had been off for ages
The display has gone off aswell
Do you think it could be the main control board this costs approx £100 or is it not worth trying as its more than that & getting to costly, terminal. Time for a new one

It`s been defrosted & stood off for a while
cheers
Any help appreciated