So I bought a cheap pocket trumpet for a long weekend trip where I still needed to practice and only had a carry-on. I just look at it as a practice tool, but it really has a fairly decent tone for what it is. Anyway, I decided to de-gunk all the brown machine oil build-up you get on those valves, brush out the casings, just get the valves moving as fast as possible on the thing. Get them all back in, cleaned and oiled up, and am pretty happy with the action. Put the horn to my lips and ffffffffffffffft. I take the valves out, make sure I have them in order, put them back in and still nothing, blocked. Getting mad, I started thinking what if the plastic tabs on this cheap piece somehow got out of alignment and now how I am going to get the holes lined up. Checked those out and they seem ok. Now I go through and put one valve in at a time making sure the holes line up, or what looks like lining up, get to the 3rd valve and wham-o, blocked. Get so irritated, I set the horn before I throw it through the window and don't come back to it til the next day. Then on a whim I put the 3 valve in the 1 and vice versa and voila, it works just fine. So...anyone with a chinese horn make sure you check whether they numbered the valves in reverse, lol.