Terminator 2

KidVidiot

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I took my Terminator 2 apart to swap wooden control panels and after plugging everything back in, the 1 player gun now jumps around the screen. I can go into calibration and the x and y axis numbers are fine and do not move unless I move the gun, but back in the game the sight starts jumping around on its own. It wasn't doing this before. I checked the bushing etc and that all seems fine, and obviously unchanged from when it was working.

There was a time delay between the disassembly and plugging everything back together so I wonder if I left something out or did something wrong. What are the two fuses mounted to the bottom of the control panel for? There's also a fuse mounted to the bottom floor of the cabinet that has a 2 pin female connector coming out of one side that doesn't seem to go anywhere.
 
The fuses on the bottom of the CP are for the recoil.

Did you plug them in backward?

Unplug them - does it still jump?
 
So, all is fine, until you start a game? Sounds like a board issue, but I don't know how. ROM corruption? What does the self-test tell you?
 
Odd behavior. I'd tug on wires to see if any break off ; pot, molex, edge connector. Then if still unfound, check continuity with meter on every trace leading to pot. Swap pot(s) with. Other gun. Drink alcohol and Kill robots...
 
I remember reading about a chip on the board that has something to do with issues with the pots/axis I don't remember what or where.
Those pots are expensive and hard to find. I had swapped the player 1 pots with new ones and they didn't seem to work any smoother so I wouldn't worry much about the pots unless they break or something.
 
So, all is fine, until you start a game? Sounds like a board issue, but I don't know how. ROM corruption? What does the self-test tell you?

I don't think it is a rom or board issue. Maybe a pot but I doubt that also. I would say it is a ground wire that is not connected somewhere and I would look for wires that are not connected to mounting hardware. Probably a green or black wire is just hanging around looking for a good home.
 
I don't think it is a rom or board issue. Maybe a pot but I doubt that also. I would say it is a ground wire that is not connected somewhere and I would look for wires that are not connected to mounting hardware. Probably a green or black wire is just hanging around looking for a good home.
Yes, I think it must be a ground wire as well, even though I thought I went through it pretty good to make sure all wires were screwed down.

If someone could take a shot of the underside of their control panel, it might help. As I said, I don't have any wires hooked up to the two fuses right now, yet the guns are recoiling. There's also a ground braid between the two fuses that isn't really grounded to anything because it's not attached anywhere.
 
Here are some pics of how it's currently wired up. Every ground wire is grounded to the cabinet. There is a ground braid on the control panel that isn't connected to anything so isn't grounded(?). I've also still got nothing connected to those two fuses (and don't see any extra wires that would connect to them) and there is the fuse on the floor of the cabinet with a 2-pin wire connection going nowhere.

The one player aim sight still jumps around, while the 2 player is fine. Both guns work, LED's work, they have recoil, etc. I feel like there is something very easy staring me in the face.
 

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Here are some pics of how it's currently wired up. Every ground wire is grounded to the cabinet. There is a ground braid on the control panel that isn't connected to anything so isn't grounded(?). I've also still got nothing connected to those two fuses (and don't see any extra wires that would connect to them) and there is the fuse on the floor of the cabinet with a 2-pin wire connection going nowhere.

The one player aim sight still jumps around, while the 2 player is fine. Both guns work, LED's work, they have recoil, etc. I feel like there is something very easy staring me in the face.

It looks to me like there is a green wire that is supposed to ground the control panel that is grounding the WOOD! I think that may be the problem as well as the braid. To me it looks like there is nothing grounding that panel. I would try that green wire on some of the mounting hardware of the gun you are having problems with. Make sure it is a ground FIRST.

I would not worry too much about the other fuse and holder at the moment. The probably went to the gun motors for the recoil and something has been changed.


It is that green wire in the lower right of the first and second pic.
 
I tried mounting the green wire onto the metal screw part on the underside of the gun. I also attached one end of the braid there, and the other end of the braid I mounted on the screw that is also holding the other ground wires and is screwed into the inside of the cabinet right above the coin door. This did not solve the problem...
 
I would try swapping the guns wiring harnesses. See if the problem travels to the gun that is currently working. If it doesn't travel then you know its an issue with the player one gun. Then you can look into maybe a gear is slipping or a wire broke loose from the pot. Do the numbers move smooth in calibration screen or are they jumping around?
 
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