AEG Santo 3798 - Motor / Sensor?

I had the thermo sensor blow about a year ago which I had fixed, it started doing the same thing again about a month ago (beeping at me in the middle of the night), and now when the motor starts, it runs for about a second before squeking and going silent for 5 mins before repeating the process... This is obviously serious as my famously cold beers are now nearing room temperature, and the freezer is starting to thaw albeit slowly!

I'm a network engineer, so I'm sure I can manage a fridge... if I could only work out how to get started ;-)

Please help!!!!