Steam from brew head, but no water

Our nearly 2 year old Cafe Roma is pushing steam through the brew head, but no hot water ... thus, no espresso. We are still getting steam through the steam wand, but for awhile, we were only getting hot water. We have decalcified many times over the life of the machine, and generally get good results. Any ideas? Anyone know how to take it apart and fix it ourselves so we don't have to deal with Breville? I hear their service is not so good.