Sony PVM-14N6U with Green Color Issue

[Tempest_2084]

I recently picked up a Sony PVM-14N6U. The system works fine, but it has a green square in the center of the screen that's much brighter on one side than the other. When an image is displayed it's not all that noticeable, but it's still not good. What does everyone think the issue could be? Is it a degaussing issue or something more serious?

http://www.atariprotos.com/temp/green1.JPG
http://www.atariprotos.com/temp/green2.JPG

[fagin]

Possible aperture grill/shadowmask problem, which if it is, means it's totally knackered.

What's it look like with an actual game running..... try getting a white screen up and take some more pictures.

I've never seen demag issues that cause such angular shapes.

[Tempest_2084]

I'll try and get something with a white screen running tonight. When a game is running its honestly really not all that noticeable except where that green bar is really bright.

[22point8]

Could be this?

[Tempest_2084]

That certainly sounds like it could be it. You can't see it in the pictures but there a faint red area to the right of the green square. I'm not sure I'm comfortable with adjusting the yoke though as you'd have to do it with the monitor on to make sure the problem was fixed. That's a good way to zap yourself.

[Tempest_2084]

I did some more tests and when the screen is all white you can't see the green issue at all. However if the game displays a black background you can see it like up in the pictures. I took some more pictures showing this but my FTP site seems to be down at the moment. I'll post them when I can.

[fagin]

If you have no issues with a white background, that would discount a problem with the aperture grill and/or a demag issue.

As suggested above, it will likely be purity control issue.

Zapping yourself should not be a concern, as long as you're sensible. Making it worse by cocking up the purity rings will be of greater concern, but as long as you mark everything up as it is, you should be OK. Again, take your time. You'll probably spend more time messing around with the magnets imo.

[Tempest_2084]

If you have no issues with a white background, that would discount a problem with the aperture grill and/or a demag issue.

As suggested above, it will likely be purity control issue.

Zapping yourself should not be a concern, as long as you're sensible. Making it worse by cocking up the purity rings will be of greater concern, but as long as you mark everything up as it is, you should be OK. Again, take your time. You'll probably spend more time messing around with the magnets imo.

I have messed around with live CRT's before, I had to fix the one in my old B&W Macintosh. However I'm not really sure how to go about this aside from move those two magnets around until the problem goes away. I'll re-read those instructions again, but I'm really not an expert on these things. Has anyone here ever done something like this before? I'm not too afraid of making the monitor worse as it was only a $10 gamble in the first place.

[fagin]

You just need to take your time. The guide given is straight forward. In any case, for $10 is it really an issue if it goes wrong.

[Tempest_2084]

You just need to take your time. The guide given is straight forward. In any case, for $10 is it really an issue if it goes wrong.

No not at all. That should have read I'm NOT too afraid about making it worse since it was only $10.