AEG SANTO Fridge - power clicking on and off?

My problem is with an aeg 3688-6ka. It started a couple of months ago, but then cleared for about 6 weeks. Some of the time i can turn the power on and it works normally for up to 1 hr (and the temp starts to fall on the read out) but the power starts clicking on and off again and the temp just climbs back up. Would be very interested in a DIY solution as I've since relocated to Spain from the UK where i purchased it and the Electrolux network here said they can't help (don't know why). A link to an exploded diagram would be helpful if one exists on the internet as would any pointers for how to test so i can source the correct parts. I'm from an IT/electrical engineering background, so don't fear having a go. The fridge cost about £650 and has had little more than 2 years use (was in storage for a long time), so I'm obviously keen to resurrect it. Many thanks in advance.