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post #1 of 11 Old 11-29-2006, 05:42 PM - Thread Starter
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I'm not sure whether this is the right place to discuss LCD monitors that are intended more for PC use than for TV use, but that's what I'm concerned about at the moment.

I bought a bargain LCD display over the holiday weekend. It works quite well, except that I'm seeing ghosting on it at some resolutions. It seems to be at its worst when the display is operating at its native resolution, 1680x1050.

I'm seeing it on both the VGA input and the DVI input. I've tried swapping cables (on both), but it's quite consistent.

Is there something simple that I'm overlooking, or is this unit defective? Or is this just typical on these inexpensive LCDs?

I've still got about 10 days to decide whether or not to keep it. I may also be able to ask them to swap it for another unit.

Thanks in advance for any insights.
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post #2 of 11 Old 11-29-2006, 06:01 PM
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Which monitor did you get? It would help to know what the specs are to determine if ghosting is due to response time or something else. Most of the newer LCDs have 8ms or less response times which should pretty much eliminate the ghosting.
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post #3 of 11 Old 11-29-2006, 07:34 PM - Thread Starter
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Quote:
Originally Posted by fdisker
Which monitor did you get? It would help to know what the specs are to determine if ghosting is due to response time or something else. Most of the newer LCDs have 8ms or less response times which should pretty much eliminate the ghosting.
It's a brand that I've never heard of before - Starlogic. But I assume that all these LCD panels are made by just a handful of vendors, with some reseller wrapping their own case around it.

The specs say 20.1", 600:1, 8ms, 1680x1050, 300 cd/m2.

The screen looks great, it's crisp, bright, good color, I really like it. But everything that appears on the screen gets repeated dimly about 4.5 inches to the right. And the ghost appears to be a negative. Where the mouse pointer is white, its ghost is slightly darker than the surrounding screen.

I already mentioned trying a bunch of different cables, but I forgot to mention that I also tried it on another computer with a completely different video card. The ghosts continued there as well. I also tried it both with and without my MyHD 130 card. No change.

If I set it to certain resolutions, like 1280x768, the ghosts are gone. But it seems to me that the native resolution should be the best of them, not the worst.

Here's something weird. If I set the computer to a HIGHER resolution than the screen can support, then Windows sets it up to scroll the display. So when I choose 1920x1080, I would expect the monitor itself to be actually operating at that same native resolution. So I should still see ghosts, right?

But no, there are no ghosts at that resolution. If I choose other high resolutions, I get some weird looking ghosts that are made up of a series of horizontal lines.

And at some resolutions, the ghosts appear only above an invisible diagonal line running from the upper left to the lower right of the screen. In those cases, there are no ghosts in the lower left, but very complete ones in the upper right.
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post #4 of 11 Old 11-30-2006, 06:47 AM
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The native resolution should be the best because the panel doesn't have to do any scaling. Are you sure you've set the proper refresh rate? It should be 60Hz. The ghosting could be due to you setting a much higher refresh rate but I'm only guessing. If it's happening on multiple computers it could just be a bad panel.
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post #5 of 11 Old 11-30-2006, 06:59 AM
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Quote:
Originally Posted by Jim Gilliland
The screen looks great, it's crisp, bright, good color, I really like it. But everything that appears on the screen gets repeated dimly about 4.5 inches to the right. And the ghost appears to be a negative. Where the mouse pointer is white, its ghost is slightly darker than the surrounding screen.

I already mentioned trying a bunch of different cables, but I forgot to mention that I also tried it on another computer with a completely different video card. The ghosts continued there as well. I also tried it both with and without my MyHD 130 card. No change.

If I set it to certain resolutions, like 1280x768, the ghosts are gone. But it seems to me that the native resolution should be the best of them, not the worst.

Here's something weird. If I set the computer to a HIGHER resolution than the screen can support, then Windows sets it up to scroll the display. So when I choose 1920x1080, I would expect the monitor itself to be actually operating at that same native resolution. So I should still see ghosts, right?

But no, there are no ghosts at that resolution. If I choose other high resolutions, I get some weird looking ghosts that are made up of a series of horizontal lines.

And at some resolutions, the ghosts appear only above an invisible diagonal line running from the upper left to the lower right of the screen. In those cases, there are no ghosts in the lower left, but very complete ones in the upper right.

Ok... how long is you cable? I ask because this sounds like "ringing" for signal bounceback. It is exagerated by higer scanning rates ( higer resolution ) and distance, and can do weird things. Try with a 3 or 6' high quality cable.

The other though is bad "overdrive" calibration. Overdive is the venacular for a technology that is designed to speed up the reponce time on LCD monitors, the problem is if it's mis-calibrated it can do quite a bit of damage to the signal.

Eric

"Any technology distinguishable from magic is insufficiently advanced" - corollary to Clark's Third Law
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post #6 of 11 Old 11-30-2006, 10:00 AM - Thread Starter
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Quote:
Originally Posted by snowmoon
Ok... how long is you cable? I ask because this sounds like "ringing" for signal bounceback. It is exagerated by higer scanning rates ( higer resolution ) and distance, and can do weird things. Try with a 3 or 6' high quality cable.

The other though is bad "overdrive" calibration. Overdive is the venacular for a technology that is designed to speed up the reponce time on LCD monitors, the problem is if it's mis-calibrated it can do quite a bit of damage to the signal.
I have two DVI cables. One is six feet, the other is nine. I also have two VGA cables. One is five feet, the other is seven. All four cables produce the same result.

The longer DVI cable came from DigitalConnection with my MyHD card. It seems to be a good quality cable. They all seem to be good cables.

I assume that there's nothing I can do about the "overdrive" problem. Is it likely that swapping the monitor will solve it, or is this likely to be consistent through the brand/model?

It isn't a huge problem - I could live with it, but I'd rather not.
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post #7 of 11 Old 11-30-2006, 10:06 AM
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Swap it out... worst case senario you waste some time and everything else is the same.

Eric

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post #8 of 11 Old 11-30-2006, 10:52 AM
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You might want to try using Powerstrip or, depending on your graphics card, the advanced display properties, and mess around with the timings.
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post #9 of 11 Old 11-30-2006, 10:54 AM
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This may also be a problem with your video card, not the display. Do you have another computer to test with the panel?
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post #10 of 11 Old 11-30-2006, 12:09 PM - Thread Starter
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Quote:
Originally Posted by chrisherbert
This may also be a problem with your video card, not the display. Do you have another computer to test with the panel?
Yes, perhaps you missed where I mentioned that above. I've seen the same behavior on two different computers using two different video cards. I've tinkered with the settings, but to no avail.
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post #11 of 11 Old 11-30-2006, 05:23 PM - Thread Starter
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Quote:
Originally Posted by snowmoon
Swap it out... worst case senario you waste some time and everything else is the same.
And that turned out to be good advice. I returned it and got a new one, and the new one is perfect. No ghosts, no issues, looks great.

I'm really happy to get this minor issue solved - this was a black Friday special, and I was not at all sure that it would turn out to be a good deal. I paid $170 for the monitor, and while I've seen quite a few 1440x900 19" monitors come in under $200, this is by far the cheapest 20" 1680x1050 monitor that I've found. Most of them are still selling at around $300.

Now I just have to hope that it holds up. :)

Thanks for all the consultation.
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