Centipede track ball

bicyclenut

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I just put a new track ball in my centipede game and it works great but it seems to keep moving when I take my hand off the ball. Is that normal or do I have something wired wrong?
Thanks for any help
 
Check your ground wires to the trackball inputs.

So I tightened the grounds and tried them in 2 different locations. Still the same outcome. I even took apart the new track ball and used the old wiring and the little sensor boards (not sure what they are called). Still, same outcome. I cleaned all the contacts in the wiring harness and cleaned the contacts at the PCB. Game play is fine, just entering your initials is impossible. It seems that if rotate the ball or slightly pick it up out of the housing its goes away briefly. Anyways, ill keep trying
 
you might have a lose connection on your connectors. though i don't understand why it would only affect your control when entering initials, however your symptoms sound like a issue with the wiring causing spurious bad connections. it is possible that your pcb is bad too, but doesn't sound like it.

have you put the game in "test mode" does the sprites in teh middle of the screen move by themself or do the grid of numbers on the left change in test mode?
 
you might have a lose connection on your connectors. though i don't understand why it would only affect your control when entering initials, however your symptoms sound like a issue with the wiring causing spurious bad connections. it is possible that your pcb is bad too, but doesn't sound like it.

have you put the game in "test mode" does the sprites in teh middle of the screen move by themself or do the grid of numbers on the left change in test mode?

Ahh..good question. I will try that now.
 
you might have a lose connection on your connectors. though i don't understand why it would only affect your control when entering initials, however your symptoms sound like a issue with the wiring causing spurious bad connections. it is possible that your pcb is bad too, but doesn't sound like it.

have you put the game in "test mode" does the sprites in teh middle of the screen move by themself or do the grid of numbers on the left change in test mode?

Thanks for the suggestion. Yes the numbers on the left are totally moving jumping from 0-1. I even took the ball out and they are still moving. So, Its not the track ball but somewhere in the wiring or pcb. On the hunt now to find this bug. Thanks again
 
Ok disconnect the trackball encoders cabling and recheck that should tell you if it's the pcb or not
 
That's actual ok. That's just a hack to provide ground when you have a bad edge connector or are worried about burning up the connector, personally I'd desolder it and hook the wires up to a .25" quick disconnect to make it easier to remove the pcb but it should not hurt.
 
Actually on second though make sure that solder joint is good and the wires are not broken it's possible that the solder joint is bad or the wires are bad at the joint from stress.
 
ok, did that and the numbers stopped. So you think its in the wiring?



Oh really? Yeah that most likely means wiring or the encoder boards but I think you said they were swapped out with another set with no change?
 
Oh really? Yeah that most likely means wiring or the encoder boards but I think you said they were swapped out with another set with no change?

Yes i just put the old encoder boards into the new track ball and still got the jumping numbers.
 
Oh really? Yeah that most likely means wiring or the encoder boards but I think you said they were swapped out with another set with no change?

Now that we are on this path, the number moved around before I replaced the track ball...I just never realized what that was meaning. I thought it was part of the test. So ok Ill hunt down the wiring. thanks
 
Ok check the crimping wires on the Molex cone tors on the encoder plugs and well everywhere in the path
 
Last edited:
Ok, finally following up on this thread. I got it working. It was the power supply. The big capacitor. Once replaced, everything works great.
 

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Ok, finally following up on this thread. I got it working. It was the power supply. The big capacitor. Once replaced, everything works great.

Hmm never heard of the big blue doing that but hey glad you fixed it nice and easy. Guess we add that to the list of big blue issue symptoms. But I'll always change them in my atari games just because they're weird.
 
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