starwars cockpit - flight yoke help needed!

[shadowman1999]

Hi there!
I’m on a restoration project on an original star wars cockpit arcade machine… I’m almost done on the cosmetic side of the project, but I have a technical problem which I’m unable to solve… I hope that some of you can perhaps give me some advice!

The problem lies with the input controller, the flight yoke. The crosshair on the screen does not move correctly. Practically the movements do not reproduce the yoke physical movements, as the crosshair keeps moving on a diagonal line between the lowleft edge and the upper right edge of the screen.
I took a video here:

All the hardware tests of the machine are ok, they do not recognize any problem. I tried to change both the potentiometers buti t didn’t change a thing! The problemi s still there… I’m starting to think that it might depend on the boards…
Can anyone of you give me a clue about the reasons and a possible solution? Or suggest something more to check? I’m really stuck on this problem!

Thanks very much
All the best
Lorenzo

[prezo1]

Maybe the force aint with you.

Sorry couldnt help that.

[shadowman1999]

Maybe not... But with the help of a Jedi Master, it might be accomplished!
Ciao!

[Level42]

Bad pot meters or bad wiring to the pot meters.

[matsadona]

Isn't there any test mode that can show the actual inputs from the yoke?

[shadowman1999]

I don't think there is anything to do with the pot wiring. A couple of years ago the game worked perfectly. I then had to make some restoration work to my house, and I kept the cockpit inside my garage... It didn't get wet, but two years in cold and wet air was no good. Many metal parts got rusted... And the yoke is no longer responding. The wiring was fine, I changed the pot thinking that they were not good anymore and got the wiring back exactly as it was on the original pots... But the problem is still there.

There is a pot test screen indeed, I'm capturing a new video so that I can post it. Will keep you posted.
Thanks for the answers!
Lorenzo

[shadowman1999]

So, here's the video I took while trying to do the pot test...


And I also have attached a pic showing where the crosshair stands when I start the game.
Any other suggestions?
Best Wishes!

[Level42]

Looks to me like the wiring is sometimes either completely open or shorted (at the moments that the line is in the top right corner.)

Turn on the pot test screen and remove the connector to the yoke and see what that line does when its diconnected. If it is continuisly in the top-right corner, you have intermittent opens in your wiring. If its in the bottom left corner, I bet something is shorting to ground.

After I rebuilt my yoke I had problems with one of the triggers microswitches, it started firing randomly now and then, turned out to be a wire shorting to the metal of the yoke = Ground.

You can also measure the pots with a multimeter (set to Ohms reading) while moving them from completely down to completely up, and completely left to completely right....there should be a steady increase or decrease in the resistance value measured, not "jumping" values....

About the starting position of the cursor, that looks normal. Its always a bit out of center at game start. The thing is that the pots keep being calibrated in software during the game.  I f.i. have made it a habit to aim the yoke quickly at all four corners of the screen when flying down to the Death Star to make it recalibrate.

[Beley]

Measure the voltage on the outside pins of each pot, there should be 5V across each pot, also measure from each outside pin to a known good ground point, one side should be connected to 5V the other to ground.

Beley

[shadowman1999]

thanks. I'm looking for a multimeter to measure the values you suggested. In the meantime, I tested what Level42 suggested.
I unplugged the Yoke connector, and switched on the self test display on the pot screen. What I see is that the line stands in the upper right corner (see attached pic). I then moved a bit all the wiring going to the boards, but the line didn't move at all. Then I plugged back in the Yoke, and keeping it still, I tried to manually move the wires that come out of the yoke. Moving the ones near the external pot, the line on the screen sometimes does small jumps but then comes back to the upper right corner. If I move the wires inside the yoke, near the inside pot, then the line slightly trembles, but no major movements.

I don't know if this can give you more clues on the situation... ?!?

Enjoy 2012!!!

Thx
Lorenzo

[Level42]

Has to be the wiring...esp. check the ground wire.