Mine had the same problem with the radio station display lights. I snapped it hard with my finger about 20,000 miles ago and the light came back on and is still on. My temp gage light was out until I hit a huge pot hole in the dark one night. It came back on and is still on after about 10,000 miles. Cost me an alignment though. I have never had my lower buttons lighted since I got my car. In fact I thought they didn't even have lights. Now this is going to bug me.
I think it is probably a good idea to slap this equipment around a bit before spending any money on it. Like smacking an old tube TV on the side, it could save a whole bunch of trouble and money, and these threads prove that it works.