I found that if the machine has sat for a while (years in my case) just using the steam wand WILL NOT WORK. I followed the suggestion of forcing water into the pick up tube that sucks out of the water tank. I used one of those injectors (like a big hypodermic) for flavoring meat. Worked right away and I’m pulling pretty good shots already. Good thing since my Rancilio Sylvia just bit the dust after 20+ years. Got the Starbucks machine a long time ago at a thrift store for $50.00. Oh did I mention it was virtually brand new? Thank you IFIXIT people!
Follow up to "Mark" Our cups seem to be under pressure, not vacuum, possibly due to altitude (over 5k ft). I push them down so the needle punctures the bottom, then repeat after turning the cup until there are 6-8 holes in the bottom. Also have better luck with the plastic k-cup you fill yourself. Before this my brand new machine was clogging and short cycling starting with the second cup!