Trackball question

[VespaGuy]

Hi all

I've already built two MAME cabinets (an upright and a cocktail), and I finally broke down an purchased my first "real" arcade cabinet. It's a Shuuz game. Except for the expected wear and tear, the cabinet is in good condition, with one exception...

The trackball is acting wonky. Occasionally, it does not seem to be registering a specific direction - down and to the right. When the game begins, you can pick one of four characters to play as, and you won't be able to pick the bottom right character.  Then during the game, you spin down/back to wind up and then spin forward/up to release, and every throw goes to the right (which I imagine is because when you spin down/back it's registering only down/left not down/right).

When I flip the panel down and play with the trackball, both of the tiny wheels seem to be spinning freely in relation to how fast the ball is spinning. I've tried disconnecting and reconnecting the "yoke" that the trackball connects to, but that doesn't seem to work with any regularity. Occasionally however, the trackball does suddenly work correctly, but I'm unsure if it's because I disconnected and reconnected the wire, or if the act of flipping the panel to get at the wire has jostled something in the actual mechanism to make it work. Not sure if it's something I've done physically, or electrically... it just suddenly works again. But within a few minutes of playing it goes wonky again.

I have no problem purchasing a new trackball if that's the problem, but I don't want to throw away $100+ to discover that the issue is with the connector and not the ball itself.

Any suggestions?

[AndyWarne]

There is some trackball troubleshooting info on this page:

http://www.ultimarc.com/optipac3.html

Although this relates to a trackball connected to an Opti-PAC, the principle is the same regardless of the interface, so this might be useful.

Andy

[RandyT]

I have no problem purchasing a new trackball if that's the problem, but I don't want to throw away $100+ to discover that the issue is with the connector and not the ball itself.

Any suggestions?

Yes.  Swap the cable/connectors on the optical boards and see if the problem moves to a different axis / direction.  Then try swapping the optical boards.  Then, remove the ball and work the rollers manually.  Note the effects of each action.  If you can borrow a trackball, or buy an inexpensive interface to connect it to your PC, it would help the troubleshooting process.

What concerns me about the specific issue you are having is that trackballs have a vertical and a horizontal axis, not "directions" per se.  It would be rare, but not impossible, for a trackball to work in the left direction, but not the right.  Usually when a direction goes out, the opposite one will go with it, or at least act very badly.  Losing two directions, one from each axis, would be very strange.

RandyT

[ghettodish]

I had a similar problem. My wiring inside the trackball case was slightly crushed in one area. Trackball worked when it was taken apart, then it would stop working when I put it back together. After widening the plastic channel where the wires fit it worked fine.

[VespaGuy]

I have no problem purchasing a new trackball if that's the problem, but I don't want to throw away $100+ to discover that the issue is with the connector and not the ball itself.

Any suggestions?

Yes.  Swap the cable/connectors on the optical boards and see if the problem moves to a different axis / direction.  Then try swapping the optical boards.  Then, remove the ball and work the rollers manually.  Note the effects of each action.  If you can borrow a trackball, or buy an inexpensive interface to connect it to your PC, it would help the troubleshooting process.

Ahhh! Thanks!! That's exactly the kind of troubleshooting I was looking for. I have no idea why I didn't think of swapping the cable/connectors.

What concerns me about the specific issue you are having is that trackballs have a vertical and a horizontal axis, not "directions" per se.  It would be rare, but not impossible, for a trackball to work in the left direction, but not the right.  Usually when a direction goes out, the opposite one will go with it, or at least act very badly.  Losing two directions, one from each axis, would be very strange.

Good points. In this case, the trackball is mounted "on the diagonal", so I am actually only losing the input from one axis, not both. However, I didn't even think about the fact that the opposite direction should be acting poorly as well, and in my case it isn't. Hmmmm... Time to start testing!

[VespaGuy]

Argh! So frustrating!!

The trackball unit is installed on the diagonal, so the four main directions (up/down/left/right) all spin both axis of the trackball.  Spinning the trackball diagonal  (down/left) should only affect one axis, and is the direction that continues to give me trouble. As said above, the opposite direction should ALSO be wonky, but it isn't. Strange.

So, I played the game for a few minutes again until the down/left response disappeared. I then opened the panel and swapped the two optical connectors. Now the X and Y axis signals should be reversed.  Because of the diagonal orientation however, when I swap the two optical connectors, up and down are reveresed, but left and right still operate normally! I've tried mapping this out in my head, and again on paper, but I'm driving myself batty.

But for now, it doesn't really matter, because every time I swap the connectors the problem disappears completely!!  I still have no way of knowing if I'm indirectly jostling something every time I open the panel... Because when I reconnect the optical connectors to their correct position, it works again! It's only after playing for about 5 or 10 minutes that the problem returns.

At this point, I'm beginning to doubt it has anything to do with the trackball itself, and more with the wiring. Since the problem comes and goes, it's going to be a huge pain trying to find out what the cause is.