Re: Omega Race

Was it like this ?

http://www.youtube.com/watch?v=0COVDNftsAg&feature=youtube_gdata_player

Sent from my iPad

On 17 Jul 2012, at 19:11, andre <livnfree_can@yahoo.com> wrote:

> This one is going to be hard to describe.. so bear with me. Didn't take pics of the first issue before it changed so will try and describe it best I can.
>
> I got to this board that played blind. I turned up the brightness and I could see the image, but full of retrace lines..etc. There was also some odd graphical issues.
>
> On the main attract screen, some of the text that was written out, like the third line, would be offset to the right edge of one side of the screen. Vector brightness was cranked up to see, so the outer border box was showing on this screen as well. When it went to the part of attract that has the game screen it was like:
>
> - main outer box of playfield was offset vertically about 1/3 of the screen, so box occupied and went off the top 2/3 of the screen.
> - The inner box of the playfield had the bottom half or so of it on the very top of screen, with top off the top of the screen, and the top half about 3 inches below the bottom half.. if that makes sense.. almost like the box went off the top of the screen, then the top drew up from the bottom of the screen, but inside the outer playfield box. When the ship starts moving in attract it goes along the bottom normally below the inner box. So when it did this now, it looked like it was travelling between 2 smaller rectangles across the center of the outer playfield box (what was visible as the outer playfield box). I can only describe it as if the outer box was ok, but the inner objects (ship, inner box, enemies..etc) all had some sort of vertical hold issue that moved them up 50%, and then the stuff off the top appeared from the bottom up. Odd thing is it was all still inside the outer box, which itself was offset up 1/3 of the monitor.
>
> So, I decided to start with the brightness issue. I had another pcb that had that and replacing the transistors in the Q204/205/206 area solved it. So I changed those out with not much of a difference. I then changed out the 7497 at A1.
>
> At that point it all changed. I now have the entire screen compressed in a single horizontal line in the center of the screen. It looks like things are moving in it in attract, but when I try to start a game, the flashing buttons pause for half a second, then start flashing again... cannot start a game now. Self test gives no errors other than the BBU ram like they all pretty well do. Tried another 7497, same thing.. checked socket for continuity..ok..
>
> Sometimes when I cycle power, I get nothing but a dot. Other times I get a dot that starts on the left side of the screen, and goes across the montior face and stops on the opposite side for half a second, then appears on the other side for half a second, and draws across the face..etc..etc.. like an EKG with no pulse. But most often I get the single line that looks like activity.
>
> I have swapped processors, have a new crystal.. all ram new.. continuity verified in ram sockets, eproms.. new Veproms programmed.. proms verified in another gameboard. Put in new ad561's, new 4016's, new tl081/082's as well as 374 at D5.
>
> The X signal is swinging DCv. The Y is not. I just picked 'Y8' to follow off D5 to E4 to F3 to G3 to G4 to L5 to L3 and all just sat at .2v. Not sure if this is the right path as I just tried to check the Y signal for voltage swings.. if I did the corresponding X one along that path it was moving on the multimeter. So not sure where the source of the issue could be.
>
> Any ideas on things to check?

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Received on Thu Jul 19 05:48:23 2012