I had this problem with my single cup unit after it had sat unused for three months. Tried the paper clip, no luck. Then I found a post elsewhere that said that if the pump dries out, it can't re- prime itself. I took a turkey injector without the needle, filled it with water and placed it over the hole in the bottom of the reservoir and gave it a strong blast of water until water came out where the coffee normally does. That did the trick.