Asteroids Pcb vertical collapse??

djw90

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Ok this is not a Monitor issue. My main asteroids Pcb works fine in this machine. This is a Pcb I picked up today. I set it on free play and put it in my working cab. Both start buttons light and blink like they should, when you push start buttons game starts as it should. All sounds work. The problem is every thing else has collapsed. The asteroids and ship are just a line. You can see the line bump abit when you turn the ship,and you can see the shots when you fire. Adjusting x and y gain on the pcb does not help. anyone have this issue?

asteroidspcb.jpg

asteroidspcb1.jpg
 
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I would start by checking or replacing [FONT=Arial, Helvetica, sans-serif][SIZE=-1]TL082 op amp at C12[/SIZE][/FONT]
 
Let's see what it looks like in test mode. It looks similar to a problem I had, although it was all over the screen, instead of just the left side.

http://forums.arcade-museum.com/showthread.php?t=116746&highlight=asteroids

BTW - if it looks like there is more picture off the screen (you can see a glow along the edge of objects moving off screen), then the problem is with one of your DAC's. If it is socketed, then most likely the socket needs to be replaced. If it's the Y DAC, then the picture shifts UP halfway. If it's the X DAC, then it shifts left halfway. Normally I would tell you to to check the deflection transistors first, but since you know the monitor is okay....
 
Let's see what it looks like in test mode. It looks similar to a problem I had, although it was all over the screen, instead of just the left side.

http://forums.arcade-museum.com/showthread.php?t=116746&highlight=asteroids

BTW - if it looks like there is more picture off the screen (you can see a glow along the edge of objects moving off screen), then the problem is with one of your DAC's. If it is socketed, then most likely the socket needs to be replaced. If it's the Y DAC, then the picture shifts UP halfway. If it's the X DAC, then it shifts left halfway. Normally I would tell you to to check the deflection transistors first, but since you know the monitor is okay....


Thanks for the post. I read your thread and it looks very similar. I will put it in test mode tomorrow and see what it does.
 
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