Plasma noise/interference issues

[bobrocks95]

I just recently bought a Panasonic EDTV (model #TH-42PW5), which was made in 2002, which I realize is pretty old for electronics but it seems to have been well taken care of. The problem I'm seeing is there's a ton of noise on the screen whenever you're close to the monitor, especially in grays and blacks. I plugged in every source/input type I had readily available and they were all very noisy. Here are a couple examples:
http://i.imgur.com/a1jCv5e.jpg
Supposed to be a solid gray, instead it's like a dumped some confetti on the screen. This is via S-Video btw
http://i.imgur.com/DnEIeGf.jpg
A fairly simple gray to black gradient, again with some bonus colors splashed all over. VGA source(also had limited color depth but I don't care to look into that atm)

Now, from what I've read this might actually be a universal problem with plasmas due to the technology behind them. If that's the case, it really sucks but I'll live, because it's not that noticeable as long as I'm a few feet away.

The bigger problem is the weird interference lines I get at the bottom of the screen. Hard to describe without just posting some pictures (these were all the Halo 2 main menu via component 480p input btw):
http://i.imgur.com/nkTj6u8.jpg
http://i.imgur.com/SDbSmc8.jpg
http://i.imgur.com/XB0ApND.jpg
The fainter noise you can see in the rest of the picture is nothing compared to these weird slanted horizontal stripes across the whole screen. In the third image here you can see the stripe is wider, which happened because I increased the contrast on the set- no clue why they're directly correlated. The stripes either way always start largest at the bottom of the screen, then get thinner and thinner until about 3/4ths of the way up the screen where they disappear. The reason I'd guess it's interference is because the lines were less noticeable when I routed the cable behind the TV rather than coming in from the front(for testing purposes with the Xbox sitting beneath the TV and the cord wrapping around the right side of the TV). Also they became more noticeable if I placed my hand on the back right of the TV's chassis. No clue what's going on there.
Tried Xbox, PS2, and Wii, and every one had those lines at the bottom. I don't remember seeing them when I had the TV facing a different way in the room, but I don't see why plasmas would be affected by earth's magnetic field or something like CRTs.

I know this may not be the best forum to post a question like this in, and I considered posting this on AVS Forums first, but every time I've posted there nobody has been able to help me and I've had to try posting here any way. So I'm hoping someone here can help! Plus they'd probably just ask me why I'm using an EDTV/older plasma and haven't upgraded yet :X

EDIT: Made the pictures links since they were humongous cell phone pics, sorry!

[brentsg]

Complaining about noise when you press your face up to a plasma is like complaining about seeing scanlines when you do the same thing to a CRT. These things are designed to be viewed from a certain viewing distance relative to display size and resolution. The higher the resolution of more recent panels allows for a closer seat.

I don't know what the last set of pics is showing, perhaps some unusual interference.

[bobrocks95]

Alright, well, I've never used a plasma before, or even known anybody who owns one, so I think I was entitled to at least be curious about the noise. I know I questioned scan lines before I knew their purpose/cause, and I just wanted to know if there was anything wrong with it. Now I know.

[gray117]

Does the noise move or is it static? It might be an anti-burn-in feature; typically I'd expect the 'noise' from such a feature to be less. Given it's an early set maybe this is playing it safe... or perhaps a symptom of age...

'Also had limited color depth but I don't care to look into that atm' - this would be more of a cause of concern. Depending on the settings, depending on the definition used you'd expect 'depth' to be one of the strengths of a plasma. But again, 2002, that's an early plasma, maybe it was just the way it was.


... There might be signal/sync/phase settings available that could improve things...Possibly unique per input. Afraid I've no idea quite how particular such screens were to [auto] adjusting, maybe even they require manual calibration?

[ryu]

i used to own a panasonic plasma that displayed similar bars when i hooked soemthing up via component. it might be the same issue, so my guess it that it's "working as intended".

[SuperPang]

I dunno. I've owned plasmas since around then and although there is a "haze" inherent with the technology which makes them crap up-close monitors, it should be uniform. A signal as poor as S-video would bleed colours all over the place but those pics look particularly nasty, although it's difficult to know what we're looking at. Turn all the picture processing gimmicks off and take a full screen pic as close as you can using a decent source (ie Component or VGA at 480p+).

[brentsg]

Plasmas use all kinds of dithering that isn't visible at a viewing distance. I would imagine that is the culprit for the first pics. It looks like dancing static pixels up close for certain content. It will be more pronounced on an older display.

[bobrocks95]

Does the noise move or is it static? It might be an anti-burn-in feature; typically I'd expect the 'noise' from such a feature to be less. Given it's an early set maybe this is playing it safe... or perhaps a symptom of age...

'Also had limited color depth but I don't care to look into that atm' - this would be more of a cause of concern. Depending on the settings, depending on the definition used you'd expect 'depth' to be one of the strengths of a plasma. But again, 2002, that's an early plasma, maybe it was just the way it was.


... There might be signal/sync/phase settings available that could improve things...Possibly unique per input. Afraid I've no idea quite how particular such screens were to [auto] adjusting, maybe even they require manual calibration?

The noise moves, slightly shifting left and right, like say the horizontal lines of distortion you'll see on VHS tapes, but much less pronounced. Since it's so obvious and changes depending on where the cable is and other factors, I'd say it's interference and not any sort of anti-burn-in. It does have a pixel orbiter, but those are supposed to move slower than the human eye can process, not this rapid wiggling left and right.

As for the color depth problem, it was only through the VGA port, and I was using a modern laptop that I wasn't able to force into the panel's native res, so it was downscaling. Since I don't need the VGA port at the moment I'm going to save the headaches for another day, probably whenever I buy a Dreamcast. There aren't any settings that advanced that can be changed in the user menu, and I wasn't able to do very much in the service menu other than alter the white balance from what I could see, so I'd probably have to open the panel and do some pot tweaking or something. Again, saving the headaches for another day. That, and hopefully it was just the laptop's fault.

i used to own a panasonic plasma that displayed similar bars when i hooked soemthing up via component. it might be the same issue, so my guess it that it's "working as intended".

I take it you were never able to eliminate the problem then, huh?

I dunno. I've owned plasmas since around then and although there is a "haze" inherent with the technology which makes them crap up-close monitors, it should be uniform. A signal as poor as S-video would bleed colours all over the place but those pics look particularly nasty, although it's difficult to know what we're looking at. Turn all the picture processing gimmicks off and take a full screen pic as close as you can using a decent source (ie Component or VGA at 480p+).

Well, the general fuzziness from the first 2 pictures is, as brentsg explained, just inherent to plasmas, so that problem's solved. The last three pictures WERE component 480p sources, which is the native resolution of the panel since it's an EDTV, and the TV is too old to have "picture processing gimmicks" of any kind. There's basic contrast, brightness, color temp, and tint adjustments, and that's it. Unless you meant my phone's camera, which also didn't have any post-processing turned on.

This is very different from color-bleeding you'd get from composite or S-Video, and I'm beginning to think it's a simple cable shielding issue, and it being a plasma is making it particularly prone to interference from crappy cables. The lines do seem to be worse with my Xbox component cables, which are very cheap third party ones, and the N64/SNES S-video cables I have, which are also cheaply made. Here's a couple more pictures I took, and while they're S-Video, I believe they'll exemplify the problem much better.
http://i.imgur.com/teLHwDq.jpg
http://i.imgur.com/II1HtvA.jpg
On the first picture, I held the cable up right next to the display, on the second, I routed it behind the display. And it's much more noticeable in person since the interference is dynamic rather than static.

Plasmas use all kinds of dithering that isn't visible at a viewing distance. I would imagine that is the culprit for the first pics. It looks like dancing static pixels up close for certain content. It will be more pronounced on an older display.

Yeah, dancing static pixels would describe it perfectly. First "problem" solved I guess, thank you.

[Fudoh]

Did you try the display with a RGBHV/VGA source ? If this works fine and if you like the display otherwise, it might be worth picking up a transcoder to have component transcoded to RGBHV.

[bobrocks95]

Did you try the display with a RGBHV/VGA source ? If this works fine and if you like the display otherwise, it might be worth picking up a transcoder to have component transcoded to RGBHV.

Actually just got all the stuff in to hook up my Genesis via RGB, but it's having problems of its own haha. The one time I tried VGA was with a modernish laptop I couldn't force to the native panel res, so until I get a Dreamcast I can't test that. I'll see how things go though!

[Fockstrot]

Did you ever figure this out? I have this problem and started googling broad plasma terms and the first result brought up this thread and your EDTV is my EXACT model. I assume you haven't had this TV for a long time though...

[bobrocks95]

Did you ever figure this out? I have this problem and started googling broad plasma terms and the first result brought up this thread and your EDTV is my EXACT model. I assume you haven't had this TV for a long time though...

I ended up upgrading from the PW5 to the PWD8UK, which was among the last EDTVs they put out. I don't use that one anymore either, but I can speak to a couple things that I figured out as my setup evolved.

For the noise in certain colors, this is almost certainly dithering the panel does to hit the expected color depth. Lots of older LCD monitors couldn't even hit 8bpp color, they'd resort to 6 bits + dithering and I'd imagine it's much the same thing for these plasmas. However, one thing you should definitely do is enter the service menu and tweak your white balance on the low end! Looking back at my old screenshots and in my experience with the PWD8, red was too strong for darker values, so you'd get a black-to-white gradient test pattern up and see a lot of noise on the darker grays, BUT that noise would be reddish and give those dark colors a bit of a red bias/push. Either the regular menu or the service menu should let you specify something like Sony CRTs' RGB Drive and RGB Cutoff settings, for the low and high-end.

For 240p content it treats it as 480i if I'm remembering correctly, and it looked back. Kind of a no-go on that front imo, unless you want to add a scaler.

For the separate problem of the horizontal noise along the screen, that was a combo of cheap cables, a cheap video switch, and the plasma being particularly susceptible to RF interference. I would try VGA straight to the display with a good quality cable, if that's possible for you to do.

Don't know if you were getting the noise or the dithering but hopefully you see this and it helps.

[Fockstrot]

For the separate problem of the horizontal noise along the screen, that was a combo of cheap cables, a cheap video switch, and the plasma being particularly susceptible to RF interference. I would try VGA straight to the display with a good quality cable, if that's possible for you to do.

Don't know if you were getting the noise or the dithering but hopefully you see this and it helps.

Thank you! I'm not getting a dithering issue just the noise and I've also come to the conclusion that it's cheap video cables. Though I tried a VGA adapter and got the same results, I think my Wii cable just sucks. My new Xbox component solution looks perfect.