DK Jr jittering when many sprites are on screen.

timply

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Original cab, original sanyo monitor. When there are a lot of sprites moving on the screen, typically on the later chain levels, it looks like the screen is shifting slightly up and down vertically where the sprites are. It can be very distracting. Both the game board and monitor have been recapped.
 
Original cab, original sanyo monitor. When there are a lot of sprites moving on the screen, typically on the later chain levels, it looks like the screen is shifting slightly up and down vertically where the sprites are. It can be very distracting. Both the game board and monitor have been recapped.
Sounds like it could be a CRT issue, probably in the power section. Possibly a regulator getting tired, when the screen loads up it starts to drop and you are starting to lose some stabilization.
 
Can you get a video of the behavior?

Things like this are always hard to diagnose with text. A video would greatly help people understand where the issue could be coming from.
 
Sounds like it could be a CRT issue, probably in the power section. Possibly a regulator getting tired, when the screen loads up it starts to drop and you are starting to lose some stabilization.
I don't think this really makes sense. More likely a board issue.
 
Can you get a video of the behavior?

Things like this are always hard to diagnose with text. A video would greatly help people understand where the issue could be coming from.
Agreed, this would help a lot.

I don't think this really makes sense. More likely a board issue.
This was my thoughts also but with no real reason I can pinpoint.
 
I can go with that.

Can you explain why you think this?

He said the screen is shifting where the sprites are. That implies the backgrounds are not moving, or at least there are areas of the screen that are not affected. Can't really think how that can ever happen on a monitor chassis.
 
He said the screen is shifting where the sprites are. That implies the backgrounds are not moving, or at least there are areas of the screen that are not affected. Can't really think how that can ever happen on a monitor chassis.
Thanks. Hard to tell without pictures or video.
 

I tried my best to get a video of it. If you watch dk jr when the bird passes above his head there is like a wave effect. Its doing that all the way across the screen, basically where any sprite is moving from right to left or left to right its the most noticeable . Its much worse on the later chain stages where there are so many birds moving across and down the screen, but its hard to find a spot where i can film long enough before dying. It's just a slight shift but when there is a lot moving it makes you think your eyes are going bad or something lol
 
That really looks like a monitor issue to me. Has this monitor ever been capped? Almost looks like the very beginning of the "flag wave" issue.

The flag wave issue could be fixed by replacing the big filter cap.

Also, what is your B+ reading? It should be 108VDC.
 
Have you tried wiping the position pots on the board back and forth? The movement is slight enough that it seems to be 'less than a pixel', so not likely a logic issue.
 
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