Keurig stops working gradually

For Christmas last year we got a Keurig single cup coffee maker. We really loved the coffee maker with the exception of the cost of the coffee pods.

After about 4 months it began failing to fill the coffee cups but this was sporadic. About two months later it quit all together. It got to the point where it would not even drop a single drop of water into the coffee cup. We only used RO water in the Keurig so I'm sure dirty water did not cause the problem. :(