The light went out in our fairly new Bosch fridge freezer yesterday. DH and I spent about an hour investigating. DH popped to Argos to get a replacement bulb, then when it still didn't work did a lot of googling to try to diagnose the problem. Called Bosch. Took all the details, said someone would call back after 8 today.
Turns out one of the kids pushed something too far back in the adjacent cupboard and turned the socket off.
So now when someone calls back we'll either have to admit our mistake, or tell them it's miraculously fixed itself.