I need tutioral or help with adjusting the color pots on the neck board

starfighter2

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I need tutioral or help with adjusting the color pots on the neck board

I need a tutioral or help with adjusting the color pots on the neck board. I have a monitor that the colors are all screwed up. The colors change as I change the ports on the neck board but cannot seem to get them adjusted so that the collor looks correct. anyone have a "how to" or set of steps on changing those pots?
thanks
 
Adjusting monitors

Here's a youtube video talking about color adjustments. He waits till about 5 minutes in to mention the test screen. If your video has a color grid or other test screen you can enter that's really helpful.
I have one with each primary color in long bars down the screen. By making them all about the same length the color was pretty balanced and a good start for some minor tweaking. It gives a good baseline and takes some of the subjectivity out of it.

Hopefully this url will survive but if not, just search youtube.com for "Arcade Repair Tips - Adjusting An Arcade Monitor"

http://www.youtube.com/watch?v=MUL5TiUYAss
 
the Wells-Gardner K7500 manual actually has an absurdly detailed step-by-step how-to for white balancing in it. I didn't understand the terminology when they meant to "ground the video signal" or whatever... apparently if you hook alligator clips to the color drive transistor heatsinks on the neckboard to ground, it will create a solid white screen (or whichever corresponding primary color you have grounded ie: red and blue will yield a purple screen)

make sure your color drives are at about the halfway point too.

I personally dial all the biases and the brightness/contrast down, step the biases up to between 1/3-1/2 way, then adjust the Brightness and Screen adjustments to where your black backgrounds appear completely black (you shouldn't see the pixels), then turn your Contrast up high enough, particularly on a screen that has text, to where there's no streaking coming off the letters. you never want your Contrast turned up super high anyway, as you're just burning out your tube faster and it looks shitty anyway.

then start adjusting the biases accordingly. if it has a purple tint, turn the green up more, for instance. do this until you achieve the best white, but don't go crazy turning all the pots up, try to stay within that halfway zone. your Contrast pot should compensate for the rest.

this is my newbie way of doing it. if you want to do it the proper way, use the WG K7500 approach.

disclaimer: I haven't white balanced a monitor completely in awhile, read Wells' way and follow how their adjustment pot suggestions are supposed to be placed at. it should be worth noting that your drives/biases if turned too low will result in a less vibrant picture, but at the same time you don't want them all hopped up either.
 
the down and dirty trick is to crank each one up untill the screen starts looking like that color all over then turn back doen untill the bleeding goes away. DO that for each pot and you should be pretty close.

If the screne looks like a photo negative, make sure you have the red blue and green wires in thier proper position at the connection to the monitor and at the gameboard.
 
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