On Sun, 31 Dec 2017 16:11:48 +0000, Stephen
wrote:

SWMBO said the freezer stopped working and would not get cold.We had
the old freezer as a spare in the garage, so we were able to use that
to save the food.

What is likely to have failed or could it just be anything? Are they
DIY-repairable or is it time to buy a new one?

I'd start with the obvious: is the fuse blown (does the light come on
when you open the door?), does the compressor run?