Asteroids - Fast blink

I'm still holding out hope I can fix it without having to drop it in the mail. So, I think I will try your suggestion above first. The image is back to being jittery like the original video I posted. I want to pull the monitor back out of my Battlezone and see if the shake goes away with different equipment. I will have to do this tomorrow though.

I am also seeing an issue where the image isn't centered. I can mess with the pots that control height and width but the image still isn't centered so the top 1/8th of the screen isn't usable. Any idea on that?


Yep. You have bad sockets. Common problem on these.

You can either clean the chips and sockets, or have the sockets replaced. The cheap option is to buy one of these:

http://www.ebay.com/itm/271103840617

And one of these:

http://www.ebay.com/itm/401280029130

And clean the chip legs, and treat the sockets. That might fix it, or it might fix it for a while, depending on how bad they are.

As for the AR, the 2N3055 (big bottlecap transistor in the center) is likely just old and tired. It should be replaced. If not that, then the LM305 regulator next, but try the 2N3055 first.


I can do all of this for you, if you just want to send it all in.
 
There is no centering control on these, as they are normally centered as-is. You can tweak any slight centering issues by loosening and moving the yoke. In your case it's hard to tell what's causing the problem though, as it theoretically could be the game board, deflection board, or yoke. I'm also still not convinced you don't have other wiring issues in this cab, give that you mentioned the harness had been mucked with.

If you have another working G05-802, that should allow you to swap parts and narrow some of the issues down. Start by swapping the entire monitor, then you can swap just the deflection boards to narrow it down further, but only if it's a G05-802 (and not a 19v2000).
 
Yes, they are both G05 802s. I will Give that a go tomorrow after work.

Thanks for all the help on this.

There is no centering control on these, as they are normally centered as-is. You can tweak any slight centering issues by loosening and moving the yoke. In your case it's hard to tell what's causing the problem though, as it theoretically could be the game board, deflection board, or yoke. I'm also still not convinced you don't have other wiring issues in this cab, give that you mentioned the harness had been mucked with.

If you have another working G05-802, that should allow you to swap parts and narrow some of the issues down. Start by swapping the entire monitor, then you can swap just the deflection boards to narrow it down further, but only if it's a G05-802 (and not a 19v2000).
 
FWIW, on Asteroids boards there is a way to isolate the CPU from the vector state machine (the part that generates the "picture") part of the board.

If you cut pin 1 at L6 (should be a 74LS42) that will isolate the VSM from the CPU side of things. If it stops resetting after you do this then you have a problem in the VSM. However, I agree with andrewb in that you have a bad socket or an IC in one of those sockets that needs to be cleaned.

Only do this if you are 100% comfortable with board repair. These older Atari boards can be real finicky.
 
FWIW, on Asteroids boards there is a way to isolate the CPU from the vector state machine (the part that generates the "picture") part of the board.

If you cut pin 1 at L6 (should be a 74LS42) that will isolate the VSM from the CPU side of things. If it stops resetting after you do this then you have a problem in the VSM. However, I agree with andrewb in that you have a bad socket or an IC in one of those sockets that needs to be cleaned.

Only do this if you are 100% comfortable with board repair. These older Atari boards can be real finicky.



Yeah, I would have suggested that if we'd gotten there. But given the fact that it was intermittent, it's not likely on the VSM side, as those either tend to work, or they don't. It's just bad sockets (thankfully, as that's an easy one, compared to VSM problems).
 
Yeah, I would have suggested that if we'd gotten there. But given the fact that it was intermittent, it's not likely on the VSM side, as those either tend to work, or they don't. It's just bad sockets (thankfully, as that's an easy one, compared to VSM problems).

Agreed. I do it just so I know what I'm getting into. Makes it easier to focus. :)
 
So I am not sure where to go from here. Here is video of my HV cage and deflection board from my battlezone swapped into the monitor. There seems to be an issue related to the new HV cage but I'm not sure if it's just a symptom of game board issues, maybe AR issues or what? Any thoughts here?



New deflection old cage

https://www.youtube.com/watch?v=YznMyfFcZBs



old deflection old cage

https://www.youtube.com/watch?v=DxLKnovFyKo


Old deflection new cage
https://www.youtube.com/watch?v=cpUz1ll1WCM


New deflection new cage

https://www.youtube.com/watch?v=cnbyOjVRO4c




Yeah, I would have suggested that if we'd gotten there. But given the fact that it was intermittent, it's not likely on the VSM side, as those either tend to work, or they don't. It's just bad sockets (thankfully, as that's an easy one, compared to VSM problems).
 
Kinda hard to tell from the video but if the caps are factory on either high voltage or deflection board they will add some noise to the image on the screen. Also, the high voltage missing the cover will probably have more jitter than the one with the cover.

As far as getting those lines straight, thats going to be tough. there are linearity pots on the board but they are factory sealed and messing with them may make things worse. Also, keep in mind that the game is projecting a "square" image on a round faced surface (the tube).
 
Hey Brian,

Ok, I watched your videos. Here's my input:

- Regarding the centering, that amount of non-centeredness is just your yoke being out of adjustment. If it was more severe, it could be other things, but that much is minor and just the yoke. Maybe one of the wedges fell out (or there are small magnets glued on some of them sometimes, which fall out), or the yoke just loosened up after 30 years (which is very common), so take a closer look. You just have to loosen the yoke and adjust it, then do not overtighten it.

Just be careful not to touch the yoke wires, and handle the plastic only, as they will be live, and you sorta need to do it with the monitor on. (I would recommend using a mirror, so you can stand behind it, and not have to reach awkwardly from the front.)

- Regarding the HV, the one big difference is that you were operating my HV without the cage cover, and the noise could easily be enough to cause that wiggling. Try my HV cage with the cover, and see if that makes it go away. If not, we can swap out the HV unit, but I think there's a good chance it's just the cover.

- Regarding the straightness of the lines, that's actually what the crosshatch is for (i.e., adjusting the picture). Note there are six controls that you need to adjust, to straighten those crosshatch lines:

+ X and Y size control pots on the game board.
+ X and Y size control pots on the monitor
+ X and Y linearity control pots on the monitor

You can adjust all six of these, and it's possible to get those lines straighter. Note also that being a very analog system (including the tube and yoke), no AD picture is perfect. I've played around with many of these, and it's not easy (or even possible in some cases) to get it 100% perfect. However you should be able to improve what you currently have.

The 6 controls are all interconnected somewhat, in terms of how they affect the straightness of the crosshatch lines. But if you play with them, you will see what they do. The 4 pots on the deflection board did originally have drops of silicone on them from the factory to hold them in place, but I should have removed them during my refurbishing, as I clean the pots as part of the work. So you should be able to adjust them with your fingers (Just be careful not to tough anything else, and remove any jewelry, etc).

Also note that the linearity pots adjust the width, but only around the outer few inches of the picture, leaving the center area unchanged. This is why they are called linearity, as they allow you to tune the picture to be linear, i.e., so the objects have consistent width across the entire X or Y axis. The key here is looking at the widths/heights of the diamonds, and trying to get the sizes at the edges of the screen the same as the size at the center, in both axes.

Anyway, hope all of this helps. Don't feel bad if you get frustrated once you start playing with everything, as like I said, it's not very intuitive. But if you try different combinations of the game board X/Y size and the monitor controls, you eventually should be able to dial it in better. However as gamefixer said, it's ultimately a straight line on a round tube, so it will probably not be 100% perfect, in all areas of the tube.

It's actually the linearity that is the most important to get dialed in, as if not, you will see the asteroids change size as they move across the screen, which can be fairly noticeable. That is more important than the overall straightness of the lines, as well as little glitches (which can also be caused by the inconsistency of the DACs and other analog chips on the game board.) Ultimately you have multiple slightly imperfect analog systems on top of each other (game board, deflection board, tube, etc), so it won't be perfect, but the system is designed to try to let you compensate for one set of inconsistency with another.

Anyway, hope that helps. Give all of the above a try and let us know how it goes.
 
Thanks for posting.....been looking through threads for this exact thing! I have an asteroids that I got a new board for (all volts good, new big blue) plugged it in and boom, she fired right up, several days go by as Im cleaning her up to bring inside, turn it on to show a friend and I got the same strange bright lines, hit side, cleared up and played fine. Next day, same thing, bright lines wont go away, unplug the monitor and power up and get the fast blinking lights p1/p2, cant go into test, cant get anything. put in cap kit for board, same thing. i havent resocketed anything yet, did check and clean, lots of black legs. just seems strange for it have been working and than striaght to this but i guess being as old as they are it happens. will follow everyones advice first from all the posts, maybe i will get lucky and resocketing will get me there. Dave
 
Hey Brian,


- Regarding the HV, the one big difference is that you were operating my HV without the cage cover, and the noise could easily be enough to cause that wiggling. Try my HV cage with the cover, and see if that makes it go away. If not, we can swap out the HV unit, but I think there's a good chance it's just the cover.

I've always wondered about this.

Is it the high voltage boards EMI leaking into the yoke thats causing the "wiggle" or the other way around? I've seen this so many times on vector monitors that were missing the cover.
 
Speaking of linearity pots ... where can you find 1.5k ohm pots for 19v2000 now that Bob Roberts is closed? The G05-802 uses 1k ohm which are easy,
 
You can use the 1K's, and they should work fine. Those pots are typically set to the middle of the range, so 1K should be enough. (Or you could use 2K's, too.) It's not critical (though it's nice to use original values if possible). I would think you could get 1.5K's through Digikey.

I actually don't replace them often (I just clean them with DeOxit), but if I do have a board with them missing or broken, I will replace them all with type 3386 sealed pots, which are the square blue type. (Note I also use these on vector boards, to replace the video adjustment pots, though they're different values.)

3386's have both the drawback and the benefit of needing to use a screwdriver (or monitor tool) to adjust them. It is less convenient than your fingers, but once set, they can't be knocked out adjustment. And they are impervious to the sooty grime that monitors love to attract, so they can't get crap in them, and will hold up better, long-term.
 
Yeah, I would have suggested that if we'd gotten there..

So, everything seems to be working great now except I have a faint don't in the center of the screen during game play. I have turned the bright and contrast down so far that everything else on the screen is faint and yet the dot remains. Once I lose my last ship and game play ends and it flips to the screen after putting your initials in the dot vanishes. As soon as I start the game the dot pops right back up. Any idea what is going on here?
 
Mine does that sometimes. My fix was to pretend it doesn't happen.

Thanks for the trimpot info, andrewb. Much appreciated.
 
So, everything seems to be working great now except I have a faint don't in the center of the screen during game play. I have turned the bright and contrast down so far that everything else on the screen is faint and yet the dot remains. Once I lose my last ship and game play ends and it flips to the screen after putting your initials in the dot vanishes. As soon as I start the game the dot pops right back up. Any idea what is going on here?


Did you try it with the other G05 you have? It sounds like it could be an issue with the game board, possibly with the Z-axis signal, which blanks the beam between objects on the screen when drawing.

If you turn the contrast up all the way, then dial back the brightness until all of the dots and retrace lines disappear, you should end up with a good picture. That's how I adjust them. But if you still have artifacts after doing this, and it's doing it with both monitors you have, then it's a game board issue, and will be hard to debug without a scope.

You also want to make sure your HV is set properly, though I'm not sure if it being off would cause the dot you're seeing. My hunch would be probably not, but I can't say so definitively. I'd lean more toward it being a game board issue first.
 
If a pin-point of phosphor is burned off of the tube, I believe, even so, that there should not be any dot of light seen. I'd suspect a leaky Zout transistor perhaps on the main board. OP got a pic?
 
If a pin-point of phosphor is burned off of the tube, I believe, even so, that there should not be any dot of light seen. I'd suspect a leaky Zout transistor perhaps on the main board. OP got a pic?

I wasn't able to get a photo last night but I did get some more observations. The dot isn't there when I first start the game. After maybe 10 min of it being on the fit shows up during game play as discribed and goes away when I lose my last ship. Does that help any with narrowing the culprit down?

I also do actually have an OScope but don't really know much about it yet souls would need pretty specific directions if you wanted me to take a reading.
 
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