Scrolling bars on my brad new HDTV [Archive] - Audio & Video Forums

PDA

View Full Version : Scrolling bars on my brad new HDTV



jsgrise
01-11-2006, 10:45 PM
I just bought a nice brand new Toshiba 62MX195 HDTV and I'm amazed byt the crystal clear image given by that TV. Watching CSI:Miami on CBS HS is like being in South Beach! But the only issue is that I can see some types of "bars" scrolling on my screen. I tought it was because my power bar was pretty cheap so I went buy a 400$ Furman Elite 15 to solve the problem but... the bars are still there!

Does anybody knows what could possibly be the cause of these "bars" scrolling on my screen? please? :confused:

Thanks a lot for your help!

edtyct
01-12-2006, 05:56 AM
Until I learned that your model is a DLP, your post made me think of the famous scrolling bars on Sony CRTs (even the very good ones). I won't bore you with the details of that one, such as they are available. Is your scrolling bar vertical or horizontal? Does it occur only on cable, or satellite, or DVD, or OTA, or is it indiscriminate? Do you notice it on HD material? Is it intermittent or continuous? Do you have any servo mechanisms in the house, electrical units that turn on and off on their own? Do you have light dimmers on the circuit? How high are your brightness and contrast settings? Lowering them about halfway won't eliminate any rampant scrolling that you have, but it may render it less visible. I take it that the Furman takes care of any grounding issues that you might have had in your system. Make sure of it. You might want to go over to AVS immediately and seach the DLP forum for your model to see whether these bars are endemic to it and how people are coping. If nothing turns up there, you're going to have to troubleshoot in the manner that I've outlined.

Ed

MCF
01-12-2006, 08:01 AM
plasma tv for months....chanced a ground loop, took out dimmers...even had my wife turn the fride on and off to see if that caused the scrolling bar....save youself a lot of time and take the tv back...maybe it is the tv and maybe it isn't, but elimating that possibiltiy is the easiest thing to do....mine turned out to be a bad power supply board in the tv. I wasted many hours of my life trying to find a ground loop that didn't exist......

jsgrise
01-12-2006, 10:13 AM
I think I have a dimmer on the same cricuit (breaker) but I don't think that this could be the problem... The bars are horizontally and I only see them on certain colors, such as the grass on a football game, specially in HD and grey and blue. The bars are only visible on a static image, like the blue backgroud of Conan O'Brien late show. I'm starting to get depress... I've tried the adjust the contrast and brightness but it doesn't really help the cause.

Thanks for the advices guys! Really appreciate them :)

edtyct
01-12-2006, 01:24 PM
I would take a gander at what the AVS forum has to say about your model before you give up on it. DLPs create their greyscale via a process called temporal dithering, in which pixels go on and off very rapidly to simulate various degrees of brightness. Sometimes the noise and flicker generated this way becomes visible, but it is usually too subtle to catch the kind of attention that you describe. DLPs are also susceptible to contouring and graininess in solid colors, but, again, these are usually slight drawbacks rather than conspicuous lowlights. Have you considered your cable or any other intermediary component as a possible cause? Are you connecting directly to the TV or using a receiver as a video switch? HDMI, DVI, or component? Switch out these variables as best you can. Maybe something will turn up.

jsgrise
01-12-2006, 06:06 PM
First of all I want to say thank you guys for your answers!

So even tough my TV has a built-in HD receiver, I have to use a Pace HD receiver. But I don't think that this is the problem because it also happens when I'm watching a movie. About my cables, I use 100$ Energy component cables and trust me, they are sheilded as hell!

can you gimme a link to that AVS forum please? I'll post a thread to see what they think about my problem.

Thanks again!

edtyct
01-12-2006, 06:56 PM
It's not shielding that I was after. It might help to know exactly the path of your signals before they get to the TV, but, honestly, I'm stretching. The relevant AVS forum is located at
http://www.avsforum.com/avs-vb/forumdisplay.php?f=63

Run a search there for your model and see what turns up. If nothing, then start a thread about your problem. Be specific about types of connection, where/when the scrolling bars appear, and how they look. Any number of things could be causing them, but it would certainly narrow the field if other people have the same experiences with that TV. Good luck.

ex-28
01-14-2006, 11:13 PM
It's not shielding that I was after. It might help to know exactly the path of your signals before they get to the TV, but, honestly, I'm stretching. The relevant AVS forum is located at
http://www.avsforum.com/avs-vb/forumdisplay.php?f=63

Run a search there for your model and see what turns up. If nothing, then start a thread about your problem. Be specific about types of connection, where/when the scrolling bars appear, and how they look. Any number of things could be causing them, but it would certainly narrow the field if other people have the same experiences with that TV. Good luck.

try a different cable for you video , i was useing svid cable a while back it was a chea one , i upgraded it to a higher end one and it solved the prob , however i am now on component.

good luck !

bacchanal
01-16-2006, 10:15 AM
I have a Sony LCD-Projection, and I can see scrolling bars at times. Adjusting the picture quality, sharpness settings helped a lot. If I get within a few feet of the tv the horizontal scrolling bars are still evident. This can happen for any source, and is not a signal issue. Bars can be present when watching SD cable, but that is a different issue.

The annoying thing about my tv is that when watching SD cable, I can see pixelation sometimes with solid colors, esp red. It happens most often on cartoons and large bright graphics, but it can happen for live pictures too. I've heard that messing with the color balance helps, but I haven't had my tv long enough to really adjust the color properly.

This really has nothing to do with your problem other than that I've noticed that the horizontal lines I can sometimes see are about same 'resolution' as the pixelation I can sometimes see. I'm wondering if it's part of the up-conversion process or if it is just the nature of digital projection tvs. At any rate, if your problem is similar to mine you 'should' be able to adjust the tv so that it is barely noticable at viewing distance. As with many tv issues, all sets have defects or certain 'traits', some are worse than others. You may just have a bad set. A good example of this is the new Samsung thin CRTs. All of them that I've seen have screen geometry problems. In some sets, it is barely noticable, in other sets it is plain as day, but they all seem to have it.

edtyct
01-16-2006, 03:07 PM
bacchanal,

I'm pretty familiar with Sony's TVs. As I said in another post, the scrolling bars on the Sony's CRTs were always native to the set at 1080i, even when Sony claimed to have sent a fix around to their authorized service people. You might never see it, but once pointed out to you, you can't miss it, though many people aren't deterred since the TVs are good in other respects. I've never seen the scrolling bars on an LCD projection TV, however. If you're sure that they aren't by-products of particular signals, I can only imagine that they're processing errors on the Sony, though I've never seen anything like them myself on a Sony, just the usual jaggies and twitters. LCDs are subject to banding. Maybe that's responsible for the horizontal bars that you're seeing.

The pixelization that you see on SD is likely to be scaling/processing error, or possibly artifacts from MPEG II. When the TV doesn't have enough bit strength in its processing, background colors can lose their consistency. Better signal processing can certainly help.