Fridge not cooling down

Hi folks, I need your help

I have a Zanussi Z1 180/80 Fridge freezer and today it stopped working. By that I mean it does not cool down any more. There is light in the fridge but its not cool. Now, the weird thing is that there is what appears like a "pump" going on every 2 minutes or so and then after a few seconds just cuts of abruptly. This pump (is it the compressor?) makes the "normal" fridge sound when the fridge working.

Do you guys have any idea as to what might be going on and if it is repairable?

Thank you

Ok an update. I tried to move the fridge and try to see whats going on in the back. As my fridge is built in and at a small height from the floor roll: ) I had to tip it over a bit so I can check on the back. I unplugged it first.

I couldnt see anything wrong (well I was trying to find a leak or something I am not an expert ) I put it back in place and turned it on. And to my surprise the normal-fridge-working noise started again (sounds like a pump/compressor). What is going on???

The freezer is getting cold again. I am not sure about the fridge since it has been on only a few minutes. I will update you as it happens. But it is really strange. I am sure its going to break down again. Any ideas as to what is going on?