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Discussion Starter · #1 ·
I am having some problems and I don't know whether or not it is the computer, power strip, extron box, or projector. It all started when I installed a new 1208 in my theater and noticed that the icons were moving on the desktop. There is absolutely no movement if I use an HD tuner (thru the same extron box) but on the desktop it looks like the icons are swimming back and forth in water. Not alot but it was noticable. The rate of the movement was directly proportional to the line rate and it was only noticed when I used power strip. I hooked up a crt monitor directly to the back of the computer (just with a vga direct cable) and did not notice the movement. The next thing I tried was a different extron box but when I hooked it up the 1208 failed to come on at all. In fact, it is now permanantly stuck in scan fail. Thanks to Curt, I should be getting some cards to hopefully fix the projector shortly.


In the mean time I put a BG808 in my theater and hooked the cables from the old extron box I was using for the 1208. The resolution on my computer happened to be at 1440 x 960 which was when I had the first failure. The first image I saw had the same movement of the icons I saw with the 1208 plus the projector seems to act very funcky on this rate so I bring it down to 1240 x 720 and it looks much more stable. There is still a very small movement in the icons but I can watch a movie fine. I try the monitor again and can not see the movement but the screen is so small it would be hard to see it anyway. What is very suspicious though is that the monitor will not accept 1440 x 960 even though it will accept 1920 x 1080p which leads me to believe something is funky coming out of my video port at the setting.


Does anyone know what might be causing this? Can bad sync ruin a Barco projector? I would rather use powerstrip but I am a little concerned about ruining another projector at this point. Any idea whats causing the movement and how I might get rid of it?


Thanks for any suggestions here.
 

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This is interesting, I experienced this on my 8500, and I brought it up once way way back when, and I think I ended up doing a full setup again, not pushing convergence as hard, and it went away. I think it wasn't a powerstrip problem because the internal patterns were "jiggling too" but then again they were synced to the input resolution. What was very strange is that it seemed only small pixels jiggled around, so like small text and icon and details. It seems that only large changes for small objects prompted the wiggling. On a gird, the lines were iron-steady, but the dots moved. Looking at someone's face, all the big stuff like their nose didn't move around, but hair details wiggled. It was really strange, I was about ready to chalk it up to my own insanity, but I dunno.


Maybe it was powerstrip. In any case now it's gone, and I haven't seen it at all on my barco, and it was gone on my 8500. Weird. Maybe try doing a setup again, it could be pushing convergence too hard? I don't know what caused my wiggling to go away... maybe it was powerstrip.
 

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Discussion Starter · #3 ·
Chris,

Thanks for the reply, that sounds exactly the same symptom. As with your case, even the internal patterns jiggled but they are moved in sync to the rate of the picture. At least you did not hurt the projector. I'm not so sure I can say the same. What rate are you using now? For some reason, the 1440 x 960 rate acts the most funky for me. I don't think the convergence or setup would be very far off midpoint especially for the 808 because I have it resting on theater seats below the 1208. Almost no geometry at all.


I'm about ready to pull out the scope and start looking at sync signals. This is a real stumper, I can't figure it out.
 

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HI,


may/may not help you BUT.......


if the video lines are not terminated I have seen this on a number of installations.


correct termination (75 ohm) has in the past solved this on a number of projectors,


It is not normally the projector that is the problem or the cause, usually other hardware in the line.


from a distance this can look like a focus issue, most ht you are close to the screen so you see icons move.


Which port do you use ??? As I understand port 3 has the termination on it.
 

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Discussion Starter · #5 ·
I would never have thought about termination but it makes sense. I am using about 10' of vga cable from the computer to the extron box. Then I am using regular coax a very short distance from the box to the projector. I am not sure what number of coax cable it is but it only runs about 5 feet or so. I am using port 5 on the Barcos which means RGBVH on the back. How would I accomplish the termination? I have some coax Y connectors I could use but that won't do anything about the vga cable. Could the vga cable be the culprit?
 

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Discussion Starter · #6 ·
Well I did a whole lot of cable swaps, projector swaps, computer swaps, and extron swaps over the weekend. First of all, I was wrong when I said the monitor did not have the problem. The monitor does show the icon movement but I just could not see it due to its much smaller display area. Swapping vga or RGB cables did not help. Swapping extron boxes did not help. Swapping projectors did not help (I have tried 2 808's and a 1208). Swapping computers did help a little. The slop was much improved with my laptop but yet could still be seen. Only at the higher resolutions though.


So at this point I think it is a computer issue but unfortunately it is not at all obvious if the display is small. Perhaps I am just too picky but I am going to open a thread in the HTPC area and see if anyone there has seen this.
 

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Quote:
Originally Posted by RVonse
I would never have thought about termination but it makes sense. I am using about 10' of vga cable from the computer to the extron box. Then I am using regular coax a very short distance from the box to the projector. I am not sure what number of coax cable it is but it only runs about 5 feet or so. I am using port 5 on the Barcos which means RGBVH on the back. How would I accomplish the termination? I have some coax Y connectors I could use but that won't do anything about the vga cable. Could the vga cable be the culprit?


If the projector wasn't terminated, you would see a VERY bright picture compared to the internal patterns.
 
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