Mine did the same thing after I cleaned for some people and left the machine in my trunk for about a week without breaking it down and cleaning it properly... totally my fault. I soaked it in a tub of hot water and vinegar overnight and tried it the next day, still nothing. I fixed the problem by buying the same machine complete with hose, and in better shape than mine on CL for 10 dollars! Now I have a spare/back up... I guess that would be good if I lent machines out because I would always have one to use myself.... but I never lend them to anyone so it's just something that takes up space for me now that I don't really have... I need to sell one of them or put it in the laundry room for someone to take... but the instant I do, the other one will break!
It was the hose, because I tried the "new" hose on the "old" machine and it worked just fine... at least it's good to know the pump didn't go out. I tried to take the hand grip apart on the old hose to clean something and I couldn't get the silly thing back together have since lost the pieces.
Good luck fixing your problem, I know how frustrating that can be! I think part of my problem was that I used Oxi-clean in it and maybe some of the granules didn't dissolve completely (why I can't imagine, I used almost boiling water) and clogged the hose.