[stevebe]

I have recently set up a Sony VPH-1271. I'm confused as to why my green tube shows lines brighter horizontally than vertically. (See attached photo)


Because of this, when I display a properly converged cross-hatch pattern, vertical lines have a red tint, while the horizontal lines of the cross hatch pattern are proper, balanced white.


I have adjusted the "screen controls " and the electronic focus controls. It seems the vertical line stays 1/2 the width of the horizontal line. This only happens on the green tube. Using the screen controls I try to get the vertical line to be brighter but the horizontal line blooms too much.


I have heard about adjusting magnets on the CRT neck - would this help my problem - perhaps something came loose while I was moving it?


The projector has 9K hours - if this makes any difference.


Any help would be greatly appreciated.

 

[kenolle]

i dont know the answer, but ive never seen a convergence screen displayed like that... generally the red/green/blue takes up the entire screen equally, making the lines white throughout the entire projected image. looks like somethings really out of alignment with all 3 guns to me. good luck... ken

 

[stevebe]

I should explain the test pattern is from a program called "Nokia Monitor Test" made for testing computer monitors. This particular test pattern displays crosses across the screen in red, green and blue. Each cross is supposed to be a single color - it's not a conventional convergence pattern. Instead, you are supposed to line up the tips of the crosses to converge the picture. I like it because it quickly shows you areas of the screen where the convergence is off - where the cross tips are not touching.


But my problem is not with convergence - I chose that pattern because it clearly shows the difference between the size of the horizontal green and the vertical green lines on my projector. The red and blue crosses provide a reference point for comparison. (They are equal in size horizontally and vertically)

 

[jcmccorm]

Bandwidth problem? What does the Avia frequency pattern look like on green??


Cary

 

[mp20748]

What scan rate/cables are you using?


This looks like a bandwidth problem. Seems like you are at your bandwidth limit.

 

[axe]

steve, have you tried setting the stig/flare magnets already? my guess is that they're off.. you can find alot of instructions on this forum.

but first check if it is a bandwidth problem as others already have pointed out.

 

[Telecine]

Good Pics !


It looks to me that it's not a case of green being brighter horizontally, but less well focussed horizontally, indicating that your astigmatism on green is out of whack.

 

[stevebe]

I took that picture at 640x480. I also notice this problem with the built-in test pattern, so I don't think bandwidth is the problem. I also tried a completely new cable - no change.


I will have to do some searching on astigmitism adjustments. I agree that it may not be in perfect focus - I did, however, think its strange that this is only happening on the green.


Thanks for the replies so far. I appreciate it!

 

[mp20748]

Can you swap neck boards from one of the other tubes?


If this problem is also on the internal pattern, I'd suspect the green neck board as the problem. Astimatism should not cause this problem.


The horizontal lines are easy, the vertical lines are the difficult ones, they require the real power (bandwidth). That's why most resolution patterns have vertical lines as the real test.