Purple Snakes, Magenta Banding on Panasonic Plasmas - Page 3

Ok. I tested my other test patterns(the ones posted in the Panasonic 60/600 problems and tweaks thread). They did display this problem before and now they're gone. I'll try all your test patterns later today, flar.

First the neon green monster on the 50Us and now this? How does Panasonic manage to stay in the PDP business?

Try adjusting your picture settings to a "sane" level.

Hey gang- New to the Panny plasma world. Friend just purchased a 42PX60u. I'll be visiting him this coming weekend to see if I can sort out some of his PQ issues before 30 day return period expires. Can I replicate this issue with green Modulated ramp from Avia? Some of you have suggested it doesn't show on gray ramps so wondering if I find it on green ramp and tweak it out in the SM. It sounds like grayscale controls at least can minimize it. Planning on bringing DVE and Avia to see if anything's too far out of whack OOB. Sounds like OOB settings are not what they once were for Panny plasmas, or at least it's a crap shoot to get one that's pretty well dialed in from the assembly line. PITA to keep swapping out just to get the right one. If it's only SM issues, just as soon fix it there and be done with it. If that won't work time for a different PDP or technology.

If the sig. sources can be truly eliminated as suspects, then I would have to agree the most likely culprit would be incorrect service menu settings. What strikes me odd is that the OP has not said anything about having an authorized panny tech, look at the panel. If it was me, and I eliminated all the obvious suspects and was still having problems, then it's time to bring in a professional.

Thanks for taking the time to explain.
I still disagree about those screenshots and I will take some close shots later to show you why I disagree.

professional calibraters have software to match correct color and grayscale

check the Display Calibration area of the forum for more information

Do you have a 360 game done by Microsoft Game Studios? If so, could you try something out? When the game loads and displays the Microsoft Game Studios graphic, press the 360 button in the center for the menu system. When the screen darkens as the menu folds out, do you get bad purple snakes dancing around the Microsoft logo?

That's an area I still see them bad, even with the SM changes. That would also support the theory about the color green as it has lots of green hues in it that turn purple once darkened.

So I tested your test patterns, flar and don't see them.

So now I'm back to square one. I restored my original Service Menu settings and checked the scene in Kiss Kiss, Bang Bang and the purple ants are still gone. I've watched the movie many times and every time they appeared there and now nothing. I messed around with the picture settings again to see if I could make them come back with no success either. The purple bands still appear on other things though so it's definitely not miraculously fixed.

I took this screenshot from approx 2ft. Just point and click (no timing adjustments) and yes, there are some weird moire effects but the palette still looks ok.
This is what I don't understand about those screenshots they took.

If you're looking to reproduce the effect that's been demonstrated here, try a shot with dark gray gradients. Misty, foggy scenes or dark scenes with flashlight beams.

How about these from KKong?
Even at 1.5 ft or so....the palatte looks ok. But WTH does this prove anyway?
Who looks from 2ft? How is this a realistic viewing distance?

Elemental1, try to take some pics from them begingin of the film, where there are like monkeys playing around, I found a lot of purple snakes in the ffrass/green stuff in the bg.

Or try Harry Potter, The Goblet of Fire, Chapter One at the 5:10 mark. Harry and his buddies are running up to a boot on the top of a hill and the sky is filled with ominous gray clouds. Check out the edges of the clouds in upper mid screen.

Should be visible from 8 to 10 feet away.

.

I'm using an HBO-HD recording on my Motorola 6412 to look at this scene on my 42" 600U. With component cables there are some faint magenta tinges on the edges of the clouds. It might be visible from a few feet away, but it would never catch your eye like that. With the DVI->HDMI connection they are more prominent - not distracting, but definitely more visible. Both were viewed using the same settings (Cinema, +12, +5, -5, -4, -20) and both scenes seemed approximately the same brightness to my eyes (but take that with a grain of salt).

BTW, it would be good to mention the equipment involved when you see these problems. A difference in DVD players, or the type of connection could affect this. There is a lot of processing of the signals from the original analog sources to our digital displays and the problems could be induced in any of those stages or they could be the result of a combination of factors from multiple stages. As I've discovered, the problem can be more or less prominent depending on the type of connection I use.

I have some pictures on my website, my first post so I can't write the whole link: (put three w:s to the beginning

cc.jyu.fi/~jakeisal -> pictures.

Yes, if my TV did that I'd not accept it or have Panasonic pay a visit to fix.
Here is that Potter shot from close and far.
Even during daytime in a crappy snapshot in a room full of light, it doesn't look like those other shots.

I was looking at the same scene from HPGOF as your first 3 pictures and didn't see anything that bad on my 600u. It was worse when I was using the DVI->HDMI connection than when I was using Component, but still not as bad as your pictures in either case. You can see my setup above here (Motorola 6412, HBO HD version to 600u via DVI->HDMI and Component).

What Picture settings were you using for the high, med, and low pictures?

What source were you using and what connection type? If HDMI, were you using YCbCr or RGB color space? Can you figure out if the color subsampling is 4:4:4 or 4:2:2?

Hi, it's easier to see the problem in a dark room. But as I can see, you don't seem to have problem. What connection you are using? I've read that there is no problem with VGA, other connections have problem.

What are the build dates on the backs of your sets? Mine is a TH-42PX600U with an October 2006 build date. I can make out faint magenta tinges here and there, but nothing as bad as any of the pics here...

All of the pics are not from my tv, I have collected the worst ones from similar thread in avforums.

edit:

Flar,
those Potter-pictures are not from my set. After spending 6 weeks in service I got new tv which has same problem but not so bad as my old one.

I will take a pic later and the PQ will be even better to the camera. I am using HDMI from a S97 Panasonic upconverting DvD player @ 1080i.

I don't know if I'm really going to be adding anything to this discussion or not, but I have a Samsung LN-S4051D LCD and sporadically across all inputs I see the exact same artifacts. It does not seem to have anything to do with the signal, as for example sometimes sitting on a windows desktop the picture will display fine for hours, and other times I can turn the set on to the problem. I can watch a movie through S-Video or Component and have it be perfectly fine, then turn around and watch the same thing the next day and have it be problematic.

The problem presented itself months past the return grace period. I called for a service appointment and the day before, after switching cable from component to HDMI the problem went away for nearly 3 weeks. Recently it returned, a few days after plugging in a Wii through component. I'd like to think component causes the problems, however after removing all the inputs and unplugging, and testing each input individually, it still happens.

In another thread a member mentioned that a service tech told him the problem was due to a bad PCB main. I have no idea what that is, or if this is even the same problem on LCDs and Plasmas, but it definately visually looks the same.

Not my picture, only Picture 0xx.jpg are mine. But I think that source is same but input, I don't know.

In general, the reason I have pictures on my site is that it's easier to see and believe the problem.

That's all well and good, but my question was more general than that. If people could post more info we might be able to find a correlation. So far all we are getting is "I've seen the problem" or "I had it the other day on my set" which does very little to narrow down the circumstances of the problem.

So, in general, when people report problems (or lack thereof), it would be nice if they would include more information on where the signal is coming from - model of plasma, which A/V component, brand, model, what kind of connection type (color space for HDMI if available), build date on set, receiver model if the signal is going through a receiver, especially if the receiver is doing upconversion (processing) on the video.

I too have seen this problem. I have the 42px60u being fed via HDMI from a Comcast/Motorola 6412 DVR. I don't remember the exact screen settings (not in front of the TV right now) but it's somewhere close to this...

Standard Mode
Brightness +7
Contrast +10
Color -4
Tint -6
Sharpness -25
Dark Enhancement: Light
Color Management: On
NR/MPEG etc. are all off

No service menu changes
Latest firmware
Manufactured in Sept. 06

Rarely do I not see this problem at least a few times every time I sit down to watch something on the TV over the course of several hours. Luckily, I'm sitting 11 feet from this TV so most of the time it's not that noticeable. Other than this problem and some more traditional looking false contouring the picture is great on this TV. But, these flaws do creep in from time to time to spoil things.

Edit: I forget to include this... Color Temp is set to Normal