Here is some history which might be important, not sure, but think I should mention it anyways.
I bought this new Happ 2-1/4" trackball on Ebay. When I got it I connected the wires to my mouse hack and discovered it did not work. After checking the mouse hack twice I could not find any problems but then I noticed one on the molex plugs on one of the PCBs was not on correctly. Instead of all 4 pins of the PCB lining up with the 4 holes on the molex connector, then molex connector was moved down one pin so only 3 pins were connected into 3 holes of the molex connector. It was over a year ago, but I might have smelled something shorting out, but I can not be sure now, but it does seem familiar know that I am thinking about it.
I placed the molex connector on properly but never could get the up/down axis working. THe left/right axis worked though. As a result, I contacted the seller and indicated that the trackball he shipped me had the molex connector not fastened correctly and my up/down axis was not working. He sent me out another PCB board for free and I still could not get the up/down axis working.
At this point I considered my mouse hack must be the problem so I decided to buy the OptiWiz and all related cable connections just to finally get this trackball working but it still did not work. The up/down axis did not work.
Anyway, I have no idea whether any of this matters, but thought I should mention this history in case others think it might be important to know.