If the Atari 5200 had one tremendously exciting advantage over all the other systems of those days, it was it's extremely solid, well-crafted trak-ball controller. If you have one that works well, you are guaranteed great gaming sessions with Missile Command and Centipede. It also works with Realsports Soccer and Galaxians, and the Millipede unreleased game that you get on Sean Kelly's multicart. But what if your trak-ball controller doesn't work so well?
That's the situation I found myself in recently, so I did a little investigation and discovered that there are a few solutions. I took pictures as I 'repaired' my trak-ball controller to share with whomever else it might assist.
Here you see what the 5200 trak-ball controller looks like when you take out the screws underneath and open it up. Be careful not to yank any of the wires as you open it.
The following are some simple things you can do to fix up a rusty trak-ball controller.
As seen here, there are 3 roller bearings which the trak-ball itself rests upon. Lift the trak-ball up. Clean it well with a soft cloth and rubbing alcohol.
Bearings #1 and #2 (to the right) are the same type of bearing. Gently take them out and clean them with rubbing alcohol. By cleaning these bearings and the ball, they will get more contact and traction with each other. Before I cleaned mine, the ball would slip on the bearings & the movement would not always register.
Bearing #3 is like an inline-skate; if you gently pry it out of its slot and spin it, it should spin for a few seconds or so. If it seems to 'catch' and stick, you need to replace it. I found mine via a site called Stella's Boneyard, by George Reese. It cost a few bucks, that's it. If you need one, do some net surfin' and post on the retro Atari boards; you may be able to find a replacement!
Then, simply put it all back together and try out your new trak-ball controller! I can attest that performing this cleaning, and in my case replacing bearing #3, changed a craptacular trak-ball controller into a nearly perfectly functioning one!