Is the compressor at the back running?
Also feel it and see if its hot to touch.
Ok in this case if its going off and the compressor isn't hot to touch its more then likely the control board on the back.
These are quite common for going like this ive replaced loads of them in the past.
If you look on the back of the appliance towards the top you will see a white plastic cover held on by a screw. Remove this and then you can see the main board and swap it over from there.
But there is also the chance it can be the thermostat board inside the fridge as again we replace loads of these as well but normal for a different fault were they get to cold. But what I used to do was replace both at the same time as to be honest they are not that expensive as parts on bekos are cheap.
But if you want to just replace the rear board first and see how it goes as its usually that board which causes this kind of fault you have now.
If you need anymore info just get back to me.
Ok the rear control board is(NNN) NNN-NNNN/p>
And the thermostat board inside the fridge at the top is(NNN) NNN-NNNN/p>