CTEK battery charger not working?

Now that the regular driving season is coming to an end, I plugged in the ctek and turned it on. The lower yellow/orage light, which responds when you press the button to move among the different types of vehicles being charged, worked fine. But the upper row of lights which indicate if the circuit is complete and the battery is being charged or is fully charged, did not light at all. Any ideas?

 

Thanks. I've left it plugged in months at a time for years. Maybe I've gotten years of use out of it and should be content to just buy another.