720 Joystick Problems

machfelon

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Ok I finally got my 720 stable. It no longer boots to garbage after replacing the PS.

Now my only issue the joystick. It will not register and movements. Sometimes it will turn a little but mostly not at all. I have two optics boards, neither one works.

When I go into test mode I can get it to say "Zeroed" but when you go to the counter clockwise turns it will only register like 1 or 2 squares. I have tried to move the board around and it still does not register. At sellers house we got it to work after making it through the test screen but I cant get it programmed in the test screen.

Also I have read something about a "LETA" chip. 1) have no idea what that is and 2) could this be the issue or is more likely the optics boards.

Is there a trick to getting it to register? I have noticed a lot of grease on the wheel when it spins but I tried to remove some thinking maybe thats it but still same issue. Joystick seems to spin relatively good its just not picking up the movements in the game.
 
I had a similar issue with mine...and it was because it was flat out missing a Leta chip. You need to get a manual, or you can find them online. When you look at the layout of the PCB and the associated key, you will find one of them labeled as Leta. Additionally, if you look at my restoration thread, you'll see a pic I posted of mine with the missing Leta chip circled. This chip is tough to come by, and my game's original was scavenged for another game. I paid $45 for the chip alone...now i think you'd be lucky if you could even find one. If you do have the chip, yours might just be bad. I don't know what it is or what it does, I just know that by getting one, my problems were solved.
 
i have a similar issue and believe the LETA is the issue. I've been wondering if the LETA could be pulled from a working system 1 motherboard that does not need the LETA without causing an issue with the system 1 board?
 
I had a similar issue with mine...and it was because it was flat out missing a Leta chip. You need to get a manual, or you can find them online. When you look at the layout of the PCB and the associated key, you will find one of them labeled as Leta. Additionally, if you look at my restoration thread, you'll see a pic I posted of mine with the missing Leta chip circled. This chip is tough to come by, and my game's original was scavenged for another game. I paid $45 for the chip alone...now i think you'd be lucky if you could even find one. If you do have the chip, yours might just be bad. I don't know what it is or what it does, I just know that by getting one, my problems were solved.

Can you link to your previous thread?

I checked my PCB and it is the original one for the cabinet. Serial numbers match the cabinet so I would doubt it was taken. It worked at sellers house after we programmed it through the test screen. But when I got it home it did not work (probably do to the PS and it lost its settings when I went back into test mode). So I will look at PCB but my guess is if it worked before even for a short time then its probably there. It may not be working though in which case I would need one.
 
i have a similar issue and believe the LETA is the issue. I've been wondering if the LETA could be pulled from a working system 1 motherboard that does not need the LETA without causing an issue with the system 1 board?

Im getting another joystick assembly next week from another KLOVER with a working optics board. Never hurts to have a spare on a game like this anyway. Im hoping that may solve my problem but I would love to get the current one working. I would be pissed to spend a ton of money on a new joystick and optics board to find out that my problem is a mystery chip.

Also why would the game boot up and start and pass all tests (cept joystick) with a missing or non functions LETA chip. Wouldnt some kind of error message appear on test or game crash without this necessary chip?
 
Im getting another joystick assembly next week from another KLOVER with a working optics board. Never hurts to have a spare on a game like this anyway. Im hoping that may solve my problem but I would love to get the current one working. I would be pissed to spend a ton of money on a new joystick and optics board to find out that my problem is a mystery chip.

Also why would the game boot up and start and pass all tests (cept joystick) with a missing or non functions LETA chip. Wouldnt some kind of error message appear on test or game crash without this necessary chip?

not sure why it would pass the tests. I assume you do have the LETA chip but it may be bad. I would venture to guess that the test is not very comprehensive and this may explain why it does not show it as bad. Personally I have tried 3 optic boards including one that was new from RAM controls (ordered pre mess). No luck on my machine. Basically on mine the stick doesn't track correctly. It moves but it's not on like it should be. When i got my machine it also worked great for a while then one day the issue began.
 
I just looked at jedidentists thread but the picture is zoomed in too close to make out the orientation of this "leta chip".

Mine sees the controller because it will set it self to "zeroed" in the controller test when I move stick to the top and release. Then on counter clockwise it only picks up first square and thats it. So when I reset game it doesnt turn or if it does only 1 degree in 1 direction which does me no good.
 
I just looked in my 720 manual and someone had drawn an X on one chip on the schematics page. The X turned out to be the LETA chip.

Listed as designator 7f Integrated Circuit, Leta Part No. 137304-1001

Gonna take a look and see if this chip is there or looks damaged.
 
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