I have descaled 2x, and cleaned the brew head and portofilter screens, but water no longer comes down thru the brewhead. Water comes out of the steam wand, and steam comes out of the wand too. No problems there. I think what is happening is that the pump is not engaging. I don't hear that customary kick in sound I usually hear when the pump goes on. What do you think my problem is? Is this something I can fix myself? Thanks for your help. I really like this machine!