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Discussion Starter · #1 ·
I received my SX21 yesterday and so far I'm impressed with its capabilities. However, I'm seeing some kind of weird artifact that I've typically only associated with old CRT monitors/TVs. Take a look at the pics to see what I mean.


I have it hooked up to my PC (Radeon 7500, 1400x1050, 1:1 via DVI). Moving around the program windows causes the artifact to move, so it's not burned in. Darker window background colors (such as a black window on top of the blue desktop) cause a more pronounced banding effect.


So far it hasn't been noticeable during normal program material, but seeing it on my desktop is enough to bother me. Any ideas what could be causing this?
 

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Jay, I tried windows on a light background and don't see what you do. I don't know if this is good news or bad news for you :(


Bottom line, must be something other than the projector. It may be that the higher resolution is allowing you to see what you didn't see before.
 

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I have never seen that with my SX21 and I have ran it most every which way & resolution possible.


Does it happen with an analog VGA connection ?

Do you have another DVI cable available ?

Do you have another video adapter available ?


- Andy


- Andy
 

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Discussion Starter · #8 ·
I also saw it on 1280x1024 mapped 1:1. I'll try some lower resolutions tomorrow.


I don't have another DVI cable, but this one has seen duty with the Hitachi 5500 (1280x1024, 1:1) and Sharp Z10000 (1280x720, 1:1) and I never saw anything like this. Same goes for the Radeon 7500 in my PC. It's never been anything but pixel-perfect.


I'll try a VGA cable and see what happens. I also have a second PC with a Geforce3 card (VGA). I suppose I can lug that into the living room and see how that looks. I find it difficult to believe that this is a problem with the PC though.


I promised myself that if after the defective Hitachi (RGB/DVI tearing) and defective Sharp (2 separate models with the same defective cooling fan) I received another defective projector, I was retiring from the projector market for a year or two and getting an RPTV. I'm tired of shipping projectors back and forth. I must have 70 or 80 DVDs I've bought and haven't watched because my projectors spend more time in transit than they do on my shelf.
 

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Are you watching windows or are you watching dvds?

I am sorry to hear that you have had problems with previous projectors. The problem is that you start looking for problmes if you spend too much time on this forum. If you are not working with the desktip picture and only watches dvds try giving yourself time off from bug hunt.

The "doctor" recommends watching at least 7 dvds in the vext four days, while abstaining from watching the windows desktop.
 

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Damn.... You really are moving through the available options...


Keep this up with another couple of returns and you will make it until the SXRD :p !!!
 

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Discussion Starter · #11 ·
Well it was bugging me too much to let it go until tomorrow, so I fired it up and checked again. It's present on 1400x1050, 1280x1024, 1024x768, 800x600, and 640x480 using both DVI and RGB connections. I think it's safe to assume it occurs at all resolutions. I also pulled an old PC with a TNT2 card into the living room, and I saw it on that one too. It was less pronounced, but I'm blaming this on the blurry output of the older card.

Quote:
Originally posted by Ohlson
Are you watching windows or are you watching dvds?

I am sorry to hear that you have had problems with previous projectors. The problem is that you start looking for problmes if you spend too much time on this forum. If you are not working with the desktip picture and only watches dvds try giving yourself time off from bug hunt.

The "doctor" recommends watching at least 7 dvds in the vext four days, while abstaining from watching the windows desktop.
That's a fine theory, but what happens when I do finally notice this during a movie? Same thing happened with the dead mirrors on the Sharp. I thought they weren't a big deal until I started to see them during movies. Then I couldn't not see them.


If it's abnormal behavior, I don't want to see it. Period. The material onscreen at the time is irrelevant. Who knows what a problem like this could develop into over time? It could get worse. Without knowing the cause, I'm not comfortable just letting it go.
 

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i have seen the same problem (with DVD's, not the computer) on my sx21 but only on input PC1 and not on input PC2. also input PC1 doesn't do 1:1 pixel mapping from my vigatec Dune-F, on Input PC2 every thing works fine.

i'm waiting for my optical DVI cable and will try the PC3 input, if it does the same thing.
 

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Jay,


I had this on my JVC G11 when I was using a CompUSA VGA cable from my HTPC to the projector. When I upgraded to a BetterCables VGA cable, this went away completely.


I'm not sure if that's the issue for you, but it's worth a look. What kind of cable do you have hooking the computer to the projector?
 

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Jay this really stinks!


I hope that it is just a cable problem. But the fact that you are seeing this via DVI AND RGB is not a good sign...



Keep us posted.


Marcus
 

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I didn't look that carefully, but if the banding effect was there at all, it sure wasn't obvious when I last fired up a laptop Windows screen using the JVC supplied VGA cable...
 

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Discussion Starter · #16 ·
The DVI cable is a 2 meter dual link cable from pacificcable.com. I got the VGA cable from copperbox.com in a package with a Key Digital transcoder, can't remember the brand. Probably OEM. 6 ft long.


I suppose it could be the cable, but is it likely that the cable will work perfectly with other projectors but cause a problem with this one? The image on the Hitachi and Sharp was rock-solid. Seeing it on DVI perplexes me because other than the dreaded "sparklies," I thought DVI either worked or it didn't.


I'm hesitant to spend $200 on new VGA and DVI cables from BetterCables without exhausting other possibilities first.
 

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Jay


Have you tried the video out from the 7500? I know it will look crappy. Have you tried different drivers?
 

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Discussion Starter · #18 ·
I haven't tried the video out, good idea. I'm wondering how much of an indicator that will be since blurring the source masks the problem. The TNT2 card produces the same result, but it's not as easy to see because it's not as sharp. On DVI, it's plain as day.


I'll also try some different drivers and see if there's any difference.
 

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You really need to try a different cable. Go to your local computer store and pick up a new cable. It's only, what, $20 at most for a 6 foot VGA cable? And DVI cables aren't that much compared to the hassle of sending back the projector. You want to eliminate as many factors as possible here...


Anyways, the banding you see is/was common on LCD monitors. I sometimes see this on my 1600x1200 resolution 15" screen on my laptop. It has something to do with the electronics inherant in the LCD's design, although I can't rule out poor EM shielding in the video connection.


It may very well be that your SX-21 has a problem with one of the inputs (bad solder joint?)...I'd try a different port if that is possible.
 

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Discussion Starter · #20 ·
This was tested on the DVI port (PC3) and VGA port (PC1 I believe). They both exhibit the same problem, but it's more pronounced via DVI because of the clearer picture. A different PC with a different video card also produced the same results, so I think I've ruled out the source.


I'll try a different cable, but any cable I find at the local comp shop is bound to be crappier than the mid-priced cable I'm already using. And since I've used both cables on previous projectors with no problems at all, I'm inclined to think this is a projector problem. The projector comes with its own VGA cable, and I have a bunch of other VGA cables floating around, so I'll give that a try.
 
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