Is it completely dead, or just not holding temperature? If its the latter, vacuum all the external vents and also make sure there's nothing crammed up against the ones inside and it might save it.
We have The Fridge Freezer That Will Live Forever. It's just coming up to 25 now and some years ago I thought it was on its way out during a hot spell so I did the above and it lives on to this day.
I should replace it, especially as it costs at least twice as much in electricity to run as a new one would, but I'm curious as to how long it will last, left to its own devices.