K7602 - All the World is Green!

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Hi, everyone. I picked up a WG K7602 as a replacement for a smashed Pole Position monitor. When hooked up, I see the game clearly, but everything is in shades of green. I've gone through a few routes to diagnosing the issue and this is what I've found:

- Everything looks fine when using another K7602 monitor (same model, swapped to test from another game).

- Swapped the green transistor on the neck board with the blue, no change.

- Connected the green, blue and red connections from the neck board with the ground, green was bright, blue and red only showed up on the edges.

- Swapped the red and green wires at the molex connector on the main board, no picture. When I switcehd them back, the picture returned, but there was some blue on the left area of the screen. Once restarted, back to only green shades.

- Tried adjusting all the color pots, only the green had any effect on the screen. Red and blue drive and cutoff didn't do squat.


At this point I'm guessing it's a bad tube. Tried tapping the neck some, no change. From what I've read, this doesn't look like a cap kit solution. Any help would be appreciated!
 
Last edited:
did you swap the neck and main pcb transistors for the color? if neither helped then either the tube or IC1 could be bad. if you need parts i stock most.
 
Yep, switched the green with the blue on the neck board. I don't think it's anything past the chassis as It looked fine when I tried a different monitor (same model). I do get some dark blues when I turn the green drive off now.
 
Hi, everyone. I picked up a WG K7602 as a replacement for a smashed Pole Position monitor. When hooked up, I see the game clearly, but everything is in shades of green. I've gone through a few routes to diagnosing the issue and this is what I've found:

- Everything looks fine when using another K7602 monitor (same model, swapped to test from another game).

- Swapped the green transistor on the neck board with the blue, no change.

- Connected the green, blue and red connections from the neck board with the ground, green was bright, blue and red only showed up on the edges.

- Swapped the red and green wires at the molex connector on the main board, no picture. When I switcehd them back, the picture returned, but there was some blue on the left area of the screen. Once restarted, back to only green shades.

- Tried adjusting all the color pots, only the green had any effect on the screen. Red and blue drive and cutoff didn't do squat.


At this point I'm guessing it's a bad tube. Tried tapping the neck some, no change. From what I've read, this doesn't look like a cap kit solution. Any help would be appreciated!

this is one of the greatest first posts I've ever seen. it's refreshing to see someone actually execute sound troubleshooting theory. and I'm not being sarcastic, you did all the correct by the book stuff.

your last test should be swapping chassis between the 2 tubes though. if the problem stays, it's in the tube. if the problem carries, then you can buy parts from security.
 
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