What is wrong with my Zoo Keeper? Vertical lines.

blkdog7

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I replaced ALL of the RAM on the video board and am still getting vertical lines on the sprites. The game is 100% playable and I installed a battery which is working well. The game is saving scores and settings. The game pretty much works fine but I have these damn vertical lines. And, it has gotten worse since I got the game going. The bricks used to look normal but now I have vertical lines on them too.

Is this a ROM issue? I installed a switcher and tried it at 5.0v and 5.1v. Still getting the same issue.

I am out of ideas and was wondering if anyone had any thoughts regarding this before I send my board to a pal.

Should I check all the ROMs? Could that be causing this? Bit rot? The ROMS on the daughter card or on the board under it?

Check it:

7.jpg


4.jpg


6.jpg
 
what do the diagnostics say? are all of the led's (that should be) lit? maybe you have a bad piece of ram. did you buy any extras?
 
have you tried cleaning the legs of all the socketed chips and making sure the pins are straight and making good contact?
 
Checked all the roms tonight and burned the coin bypass ROM. Same deal. Vertical lines.

Gonna touch up all the RAM sockets next. Running out of ideas....
 
You either have a bad RAM or a bad RAM socket. Verify that you have the correct speed RAM also. I don't recall the speed off of the top of my head, but it is listed in the scat IIRC. 150 is what comes to mind, but it might be 250 I just don't remember.
 
You either have a bad RAM or a bad RAM socket. Verify that you have the correct speed RAM also. I don't recall the speed off of the top of my head, but it is listed in the scat IIRC. 150 is what comes to mind, but it might be 250 I just don't remember.

Wrong.,,,,,
 
Replaced the 6809E CPU. Same deal.

Gonna look at those RAM sockets next. But, I have no RAM errors when doing the self tests using the coin door switches. Ugh. The PCB self test button is screwed up when I do it.
 
Here's an interesting thing about my issues:

When playing a two player game, player two has different graphical issues.

For instance, player ones graphical issues seem to affect the top and bottom sides of the level's bricks as they are created. Player twos bricks are only affected on the left and ride sides of the level. The bricks on the top and bottom sides of the level look fine for player two.

Why would the issues be different depending what player is playing?
 
I did check all of my ROMs. Adam was at my house last night (the guy that made that video) and he didn't have any ideas. He was gonna look at the schematic and see if anything jumped out at him. He usually does Z80 stuff with his FLUKE.

Was just wondering if anyone have seen graphic issues that were different from player to player.
 
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