Happs trackball problem

[Samanai]

My trackball is having some trouble registering up and down movements (i.e. away from me and towards me; the Y axis?), but no issues at all with left and right.  Basically, it just barely moves (if at all) when you try and get it to go up or down on the monitor.  This is the case whether it's acting as a mouse or as a controller from within a MAME game.  It worked fine for 6 months up until last week.  Any thoughts on what the issue/solution might be?

[polaris]

dirt?

[WLVRYN]

Are you using an encoder or is it a USB model?  When I first got my trackball using an Optipac, I had similar problems.  I switched the wires out of the player 1 trackball inputs into the player 1 rotary device inputs and it worked fine.  I then attached my spinner to the player 1 trackball inputs since the horizontal movements were not a problem.  I'm pretty sure it was the Optipac since i could switch the wiring on the X and Y axes and I still had problems with up and down movements.  I havent had an problems with it since wired up that way, so its no big deal for me.

[Samanai]

I'm using the Optipac as well.  It's worked fine for months up until now, but I think I'll give your solution a try, just in case (and because it makes sense).  Thanks.