Donkey Kong maroon screen

learpilot2

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HILTON HEAD ISLAND, South Carolina
I bought a donkey kong that when powered up the screen is all dark maroon in color. The game plays fine except for the god awful speaker hum. The screen background is not black at all, just maroon. There is also a black right side vertical line on the right edge of the picture. I think it is foldover. Here is the weird thing. After the monitor warms up for 15 minutes, the background slowly goes to black with just a tinge of maroon. Almost normal but not quite. Black right egde foldover is still there.

I figured I just need to cap it. I tore out the chassis, and everything is very dusty except for all the bright and shiney caps! It looks like it must of been re-capped sometime recently. They did not do the audio board caps hence the humm.

Question is should I pull out all these nice looking caps with like new solderjoints, and recap it, or is this just some sort of monitor adjustment. Should I recap only the audio board, and reinstall, and make some sort of monitor or b+ adjustment?

Hate to replace shiney new looking caps for no reason. Now that it is out, maybe I should recap?

Does anyone have a good link to a cap map for the 20ez? Mine stinks. Thanks,

Rick
 
Warming up and clearing up is a good indication the caps are simply charging up. Recap it for sure.
http://www.jeffsgames.com/images/arcade/misc/sanyo20ezcapmap.pdf

As far as maroon background sounds like the red gun is being over driven and if the brightness on the flyback or chassis itself is set too high it'll just amplify it. Turn the brightness down so the monitors back ground is black - not a light black but black. Then adjust your red gun and see what that looks like. However, keep in mind it's fairly common that after a recap you need to re-adjust your colors and brightness again.
 
caps labeled np

I found some caps that had no polarity markings on the cap or pcb. They were labeled 4.7uf 25v NP. Does the NP mean no polarity. In other words I can't screw up which direction I put it in?

Thanks
 
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