I know it’s an old thread but just one more thing to add. The descaling works, I had this exact same issue and followed the vinegar steps above and yes it started pumping water again without the portafilter. The 2nd issue I had was the screen on the portafilter was completely blocked so when I added the portafilter, nothing was coming out still. To clear this, you need to burn the blockage away. Since the screen is blocked with dried coffee bits, they can be cleared by burning vs poking each hole out. I held mine with thongs and used a lighter for about 30 seconds a time and rinsed it under the sink after each time. As I held the filter to the light I could see more and more holes opening up. I repeated this until most of the holes were opened. After doing this with a combination of descaling, it’s like I have a brand new machine. Thank you to all who posted answers here, it really helped.