Star Wars Yoke Pots

Zinfer

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What the heck am I doing wrong here? I've got no control at all. I went into diags and this is what my pots are telling me. I'm getting no up or down or left or right.
I installed this supposed 'NOS' Star Wars yoke harness I bought from Arcade Adventures. I'm going black/white/red to each pot. My triggers are all ok. The Pots are both brand new.
Anyone else have problems with SW yoke calibration?
IMG_1928.jpg

I guess the 10D and 10EF are the option selected.
 
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I'm wondering if that green earth ground wire/clip can cause your stick not to operate? The 'NOS' harness I bought never had that on it. I have the old one. Would it help the stick to center if I attached it to the molex? I'm thinking it just connects to the green on the other side of the molex.
I've tried putting my yoke in all 4 extreme directions. I've even tried a fire button after aiming it to all extremes.
flickering lines, that's all I see.
 
This is a pic of an Empire Strikes Back yoke that I have setting here. So your wiring sounds correct. Have you tried taking the gear off and rotating the pot all the way one way and then the other to see if the movement shows up on screen?

Gearsandsprings.jpg
 
I did try removing the gear towards the end of the yoke and running small adjustments, nothing extreme. The one up at the front was just too hard to get to to turn it.
I was sure to take a meter to both pots to find their center before assembling. By the picture of my calibration, it looks completely wacked.
Wish I had a couple 5k pots extra. Those are both 5k pots right? There's no chance of getting them reversed?
I would have expected minor adjustments but this is really off.
 
I'm pretty sure they are 5K pots. If you metered them and they moved smoothly though their range, then they are working. Something else must be wrong. You might want to check for continuity from the pot back though the harness to the board.
 
I'm going to post a video on youtube. this is very irksome. I am so close to actually being done with this. Be nice to at least play a game now. I'll letcha know when I get it uploaded.
 
What is it doing without the yoke connected at all? Same thing?

The potentiometers in a Star Wars are acting as simple voltage dividers. You put in the +5V on one end of the pot, and current flows to the other end, which is grounded. The 'wiper' of the pot (the thing you move when you turn the pot) 'picks' off a voltage anywhere between +5V and ground and sends that back to the MPU board.

Potentiometers are easy to check with a multimeter. Put it in ohm mode and see if you get 5K resistance across the whole thing (meter between the two pins at the far ends). Then see if you have adjustable resistance between that middle 'wiper' pin and either one of the ends. You should be able to tune the resistance between the wiper and an end pretty much anywhere between 0 and 5K ohm.

It is possible to miswire potentiometers. Are you sure you have red on one 'end' of the pot, black on the other end, and white in the middle? I would double check the schematics and make sure that you don't have two wires crossed. Double check the wiring on your NOS harness too. It is not impossible that someone switched a few pin locations at some point. (Stranger things have happened in op warehouses.) Another possibility is that everything is aok with your pots/yoke/wiring but you have a bad chip back on your boards.

The ground wire that clips to the yoke is a safety ground. It is there to make sure that no one playing your game gets shocked by touching the yoke if something shorts within the game. It has no bearing on the functionality of the potentiometers in the yoke.
 
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Long time no see Zinfer.

To the contrary, the CPU sees up, down, left and right because they're STUCK in the photo. get yourself back to that screen, and unplug the yoke harness. If those three lines change/vanish at least you isolated to the yoke side. Since I don't see you mention WHY you bought a replacement harness in the first place, it leaves me to assume you had problems before, and thus it could actually be on the PCB, not in the yoke? Also, 10D & 10EF are your on PCB DIP switch settings reflected for your convienence.
 
Hi Matty. When I bought the project, it was wood only. All the hardware had been purchased seperately and assembled. When I purchased the yoke in particular, the harness had been cut up and there wasn't much left of it. So I had to find a harness complete and unhacked.
I will try unplugging and see what I have. I'll check all this out today.
Without knowing yet if it's wiring or bad pots, just what chips are involved in the yoke input?
I should have something new by tonight hopefully.

Long time no see Zinfer.

To the contrary, the CPU sees up, down, left and right because they're STUCK in the photo. get yourself back to that screen, and unplug the yoke harness. If those three lines change/vanish at least you isolated to the yoke side. Since I don't see you mention WHY you bought a replacement harness in the first place, it leaves me to assume you had problems before, and thus it could actually be on the PCB, not in the yoke? Also, 10D & 10EF are your on PCB DIP switch settings reflected for your convienence.
 
Ok, I pulled the yoke molex and this is what I got:

IMG_1943.jpg

I also looked over the schematics with the yoke harness and SW side of the yoke harness and all wires are where they are supposed to be. I metered the roll Pot and got 3.5 on one side and rotated the pot to the opposite and got 4.1 on the other.
The only thing I didn't do was run voltage measurements on the sw side of the yoke while the unit was on. It's looking more like it actually could be a chip on the board but I don't know which chips to look at to run a logic probe on. Just to cover all the bases, I also ran continuity checks on the red/black/white lines leading to both pots.
 
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I am working on a Star Wars at the moment and have my boards and schematics out on my test bench. If no one beats me to it, I can give you specific information on which chips to test and what they look like tonight.
 
Ok, here is what the schematic says:

Photo%20May%2016%2C%208%2044%2038%20PM.jpg


Pitch and yaw are the outputs from your yoke pots. (Apparently thrust didn't make it past the prototype phase! heheh..) Anyway, if you can sort through all of those pin labels, you will see that the chip in question is at location '9K' on the MPU board. The chip location labels are screened in tiny yellow letters to the sides of the chips. Here is a picture of the chip in question for ease of location:

Photo%20May%2016%2C%208%2047%2050%20PM.jpg


That red thing at the bottom of the picture is the cable that interconnects the MPU board and the small sound board. As you can see, that chip has 'ADC' in the title, i.e. 'analog digital converter'. Fortunately it is socketed. I would try removing the chip and gently cleaning the pins with a fiberglass pencil (or some scotchbrite) and reseating the chip to see if that makes any difference. If that doesn't fix it, it is time to break out a multimeter or scope and probe the input pins 26 and 27 and see what kind of voltages are making it back to the chip. (Some mini clip leads would come in really handy here.) Make sure the voltages go up and down when you move the yoke/turn the pots. If the voltages are missing/messed up, you may have a harness problem. (Some pins on the edge connector may need to be replaced.) If the voltages are doing what they should (varying between 0 and 5 V roughly), the chip may be suspect.

If nothing above works, you are at a point where you could try subbing in a known working chip. If a known working chip doesn't get you there, it could be the socket, or logic elsewhere on the board (see next paragraph).

Take note of data lines D0 through D7 leaving the chip (in the schematic) on the right hand side. That's where the digital numbers that contain the potentiometer locations are read out. There is always a possibility that something is happening to screw up that data before it hits the CPU, but we can cross that bridge when we come to it.

I hope this helps!

-Jude
 
Thanks for that info. I pulled the ADC out and cleaned it. Then reseated it. No influence. I then used a meter from the back. Checked Pin 27 and found I started out with approx 2.31vdc. I hand crank the roll gear to one side and get 4.91vdc. Crank it to extreme left and get .500. I checked pin 26 and got something like 3.25 volts with no way to reach the yoke unless I unmounted it and brought it to the back of the cabinet.
So perhaps the ADC0809CCN is having some problems.
I'm thinking I may try ordering a ADC0809CCN from Mouser. Expensive suckers. But not overly so. Definitely not going to maintain much of a stock of them.
 
Jude --Dude you are awesome man.
I just happened to remember I had a spare non-working Star Wars Main pcb boxed up in the closet. I pulled it out and it had the ADC chip in it. I pulled the IC out and swapped it into my Star Wars boardset.
The result was immediate.
IMG_1944.jpg

Some final adjustments tomorrow and I can finally throw the cover on the yoke and call it done.
Thank you so much for your fantastic diagnosis. I'll have to get one of those on order from Mouser to replace it as I try to get that spare MPU going. I really enjoyed playing that test game.
 
Can I get a 'kinda sorta awesome' for shooting you off in the right direction? LOL! Nice follow up by Jude, I was working on the new work area all night :(

- Matt
 
Congrats on getting your game working! The lows of frustration in this hobby can be annoying, but they are worth it when everything comes together. It's a good thing you had that spare boardset handy. Have fun blowing up the Death Star.
 
Yes that's exactly what I did. Wanted to see if there were a major difference between the WG6100 and the Amplifone with the explosion. It exploded rather well. :D
As for Matty - Hahah - you did say to unplug the yoke - which that hadn't occurred to me before to do that. I just went all apeshit on Jude because he focused on that IC like a friggen LASER. Awesome catch and yea - now I'm glad I bought that dead board on Ebay. lol.
Man I am amped! Thank you thank you thank you.
 
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