[brh986]

This was posted before and I've been trying to work with curt to resolve this issue to no avail.


"I sold a retubed 9500LC (new MEC tubes!) about a month ago, and the set is working fine, except for a fine drive type line down the screen. I'm cutting and pasting the customer's description here, as I hvae not seen this before. Any ideas?


Thanks!


It really isn't possible to get a decent picture of the screen that shows the line. It's hard enough to photograph a decent entire picture reflectigng off the screen let alone a tiny line. You can see it very clearly in person but only during certain dark scenes. I'm 100% positive that the reason it's not more apparent isn't that the line is not bright or not a problem but just that it's so thin. The line is not more than 2 pixels wide and probably only 1 pixel wide but it is absolutely at 100% brightness, very bright. Only on a white field can it nto be seen on the tube face. I checked the G2 and drive levels and set them a little bit below where they should be. The red and blue tubes are right where they should be but the green tube needs to be a little higher than spec.


There is something that makes it go away though, any kind of onscreen display seems to make it disapear as well as any of the test patterns. Otherwise with either no signal or ANY external signal the lines are always there. What do you think is causing this? It's annoying when it shows up in dark screens but the biggest concern is that it will eventually burn in. As I said it appears to be a 1 pixel wide line that covers the entire verticle of the raster that always stays lit at 100% brightness on the blue and red tubes and ocasionally on the green but at a lesser intensity. Do you understand what I mean about the line? It's probably hard to get an exact feel for it without seeing it in person. The general "noise" on the red and blue tubes also baffles me. Why would there be any kind of artifact only on the blue and red tube but not the green? "


Since the original post we have tried swapping the VIM twice and a third tim with a VIM modified by Mike Parker. Curt told me that the guys at VDC said this was a common defect in the earlier 9500 LCs and that a new or modified VIM would fix the problem but unfortunately it hasn't. Does anyone else have any other ideas? Thanks.

 

[mp20748]

Yes I remember this. The board that was sent to you, has the line mod updated on it, therefore it has what VDC mentioned. That board was also tested here with no problems noted.


The difference that you indicate for both blue, red and green CRT's leads me to think that the problem could be on the neck boards, especially if this same problem was noted with the various VIM changes. There are several things that could cause the lines. But first, try swapping the green and red neck boards to see if the problem follows.

 

[brh986]

Quote:

Originally posted by mp20748 Yes I remember this. The board that was sent to you, has the line mod updated on it, therefore it has what VDC mentioned. That board was also tested here with no problems noted. The difference that you indicate for both blue, red and green CRT's leads me to think that the problem could be on the neck boards, especially if this same problem was noted with the various VIM changes. There are several things that could cause the lines. But first, try swapping the green and red neck boards to see if the problem follows.

Since the problem is aparent on all the tubes how could it be expected that swapping the neck boards between tubes would change the symptoms? Thanks.

 

[mp20748]

Quote:

Originally posted by brh986 The red and blue tubes are right where they should be but the green tube needs to be a little higher than spec. The general "noise" on the red and blue tubes also baffles me. Why would there be any kind of artifact only on the blue and red tube but not the green? "

If you swap the boards and the problem noted above follows, it's an indication that there is a problem with the neck boards, and not the VIM. Also, If you've seen this same problem (above) on the other VIM's that would more likely rule out the VIM's.


It's not uncommon for all three baords to share the same defect on the Marquees.