There were a couple of items omitted from this post. 1. When you remove the first two screws, the cover is still connected to the lower assembly by two posts that are pressed into the lower part. Holding the cover near the back and wiggling the sides up and down will pull the posts out so you can move it. 2. On my version of the keurig, there is an assembly that holds a one way valve. That was the problem with mine. I removed the assembly, tried to blow through it and couldn't. I pushed on the back of the valve and it came loose. Problem solved. I took a picture of the valve assembly but couldn't figure out how to attach it here. I'll add it elsewhere if I can figure it out.