Korean AP-0621 green screen

GoneMad

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I just come across this chassis. Tube is in great shape(no burn) but the chassis has a lot of rodent work done to it. After cleaning it up as best as I can and recapped everything I could with what I had on hand, about 80% of the caps, I hook it up to my robocop and turn it on. The game boots, coins up and plays blind. I can only get this green screen and no matter what adjustment pot I change, it makes no difference on the screen at all. It's hard to find much info on these so I hope someone can start me off in the right direction.
 

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Well, after doing some research and watching this little video,(hats off to the creator of this site) I tested the tube and it seems when I ground all the connections of the said points, I get no change at all. According to the site, my tube is hosed. Can anyone tell me if this theory is 100% accurate before I pull off this tube and look for another?

http://www.arcaderepairtips.com/2011/03/23/checking-a-monitor-tube/
 
If you're getting that on the screen, then there is at least some life in the tube. You should be able to see some sort of video signal.

It think you're missing a voltage to the neckboard. Check for breaks in the wiring to the neckboard, and look for cracked solder joints and open resistors.

-Ian
 
OK, I would like to get this going because I have a Track & Field on the way I would like to use it in, if I can get it working. I reflowed the neckboard still the same. Checked for any cracks and broken traces. Board seems to be in pretty good shape. I started to check resistors on neckboard. There are three that are all 2W 5.6K OHM. One measures right at 5.6K but the other two are measuring at 5.38K. Could this difference be the root of my problem or should I keep going?
 
Great, will do . Thanks for the good news ;)
What I forgot to mention, it makes no difference if the pcb is plugged into the chassis or not. The only thing that makes any difference on the screen is the brightness adjustment on the flyback.
 
I took another kick at this to see what I could do. I replaced a few corroded resistors on the main pcb and hooked it up. When I had it on, I grabbed the neck board just to wiggle it a bit to see if there may have been a bad solder somewhere or something like that. My finger touched on one of the three resistors. HOLY SHIT, for touching it for a split second, it blistered my finger pretty damn good. Should they be that hot? And when I say split second, I mean half a second, if that and it give a nice little white mark across the tip of my finger. That's not right, is it?
 
OK, I'm gonna revisit this one, now that my G07 is finally spot on. I was checking all the resistors on the neckboard and referencing the values on them according to this http://home.comcast.net/~mtpacifico...rean Telecom AP-0621 Parts and Schematics.pdf
Most of them were right on, but there were a few that were off by one or even two hundred Ohms. Would this be big enough variance to cause this problem?

edit: Also upon further inspection, i noticed a few solder joints that look like they could be bridged. Here is a pic
IMG224.jpg

They are part of this row of resistors
IMG225.jpg
 
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