uConsole Trackball Issue

Got my uConsole assembled, but the trackball won’t scroll down, I mean the mouse won’t go down when I scroll down. Up, left, and right directions work fine. I checked the axis on the trackball, it seems okay. Any ideas on the cause?

I’m experiencing a similar issue. The trackball scrolls up and down without any problems, but I’m unable to make any lateral movements.

I haven’t found a solution yet.