Panasonic 11G/12G/13G black levels have seemingly doubled overnight? - Page 2

[quote=Orta;16934747]Thanks bat, useful bit of info to have. I had tried doing this kind of reset myself, but could only find the "Store Mode" reset that's in the manual. Sadly, this didn't seem to do anything for my problem. Black levels weren't affected at all. Do you remember any of the other potential solutions they had you trying?


The other suggestions made were to check my connections, make sure it wassn't something going bad with the hdmi or component board, but if it happens when using the side hdmi then its something else because this connection isn't on the same board as the other two, so after that he wanted to know about my player's and set top box, but all of this checked out fine of course, so next he said the only other options were to do the reset, schedule a repair order to have a tech check the set out, or have it pro calibrated to suit my black level desires, but fortunantly the reset worked for me. sorry i don't have any better info for you to go on..........

I know this is a n00b question but this is my first set. Are the blacks supposed to almost blend in with the panel? Cause my blacks are a little lighter than the panel.

Just checked my G10 hours of usag, and it was 01026:20, if i read this correctly it would mean i've put more than a 1000 hrs on the set so far.
just figured i let you know how my hours of use stood compared to yours orta.....

Have you tried the "self-check" reset I described on post #27?

This is going to be a tough problem to explain, when i was trying to explain it to the panny rep for the first 10 min or so he couldn't quit understand what i was saying but we eventually came to an understanding. At least you do have the equipment to show them what you are talking about, by the way just keep us informed if you don't care i'm real curious to see how they resolve the problem........

If my replacement G10 does this I will be quite upset (getting my current unit replaced due to static vertical lines) and Panasonic will be hearing an earful because that would basically be false advertising.

(how would the 9g Kuro owners like it if after their set hit 500 hours the black level went up to normal Panasonic levels (.08) I think that they would be quite mad.)

You need to accept that PDPs change with age. Some have programmed changes to account for it and some don't. Either way, you cannot expect a set to stabilize for at least a couple of hundred hours. They continue to change over the life of the phosphors but it will be far less noticeable and will usually not involve as much shifting in the activation levels as early on.

lcaillo,

Technical (or marketing) question: If it is possible to 'program' the black level, why do the manufactures not set the black level 'blacker' initially and let the panel drift to the level where it now starts off? I hope my phrasing is not too obtuse.

EDIT: fixed typo

Larry

Minimum luminance levels should never increase over time. I do not know of any PDP manufacturer that has programmed changes on this level.

For those who are seeing this black level change, have you been in the SM?

D-Nice,

Interesting.

I have been in the service menu for all my Panasonics -- 42px60, 42px75, 42 & 50px80, and 42 & 50x1 -- and have never seen any significant increase (or decrease) in black level using an i1d2. That's with an initial calibration at about 150 hours and another at about 1000 hours.

Larry

I don't recall which vendor it was, but I was at service training that included 6 TV makers last year and one of them specifically said that there was a programmed change in the ramp timing and voltages to account for changes in activation characteristics as the panels aged in. It may have been Panasonic but I do not recall. I do know that they age the Pro units 300 hours before they leave the factory. I do recall the changes having to do with the ramp up and ramp down to reset timing and voltages for Vset and -Vy.

There is a very clear tendency in many PDPs that I have seen from Panasonic and NEC that I have observed very carefully over the first few hundred hours to decrease low level activation noise. This effectively changes the black level of the set. If there is a programmed change to accont for this it very well effect a change that is notable if one is trying to carefully calibrate black levels.

Try measuring them right out of the box then again later.

yes, i went in and checked hours of service, i also put in orta's offsets that he posted a few weeks ago.....but i noticed this even on thx, the offsets were used for custom only, no changes were made to the thx. Also his offsets were just for the color, red, green, and blu drives and cuts only......can this still affect the mLL's, i mean the change was rather drastic and very noticable, for me at least....

Wouldn't it be unwise to calibrate out of the box anyway? Shouldn't you wait until the TV has been broken in first? Isn't it normal for all PDP's to look different after the break-in period?

Why would I measure a virgin set? Anyway, my black level measurements for all my models were extremely close to the calibration results for the same models that were posted in the calibration forum. Don't have the vaguest idea how many hours were on those sets.

Larry

If you want to learn whether and how they change over time you might want to do so. That is what I did and found significant changes in the first 200 hours. I had always noticed that some PDPs looked more noisy when OOB and seemed to settle down over time to looking cleaner.

Perhaps the newer models are more stable than in the past. I have not made these kinds of measurements in a couple of years.

None of what you posted occurs outside of final assmebly and QC.

lcaillo,

We agree that the parameters change in the panels early lifetime. That's why I never bothered to measure the black level before the set was mature. Maybe I'll try in on next years entry model.

Larry

Phosphor aging is normal on any and all phosphor based displays. Specifically speaking on PDPs, yes there are still significant shifts in the RGB channels, but none of those shifts would ever cause a significant increase in minimum luminance levels. The noise seen on OOTB PDPs is caused by the voltage. However, that voltage does not change over the life of the panel per a pre-planned algorithm.

Vset and Vy have fixed values on my X1s.

Larry

All PDPs have "fixed" voltages, but that is only part of the story on how they operate. The timing of the ramp up to Vy+Vset and down to -Vy is very important.

Thirty years of servicing and calibrating electronics have taught me to never assume that I know everything a manufacturer is doing in a product. This is more true than ever with the large scale integration and programability in today's products. I cannot tell you what your particular set is doing or not doing, but I can tell you what I have learned, and the most important lesson is not to assume anything. We just don't know what we don't know, and vendor documentation on design and operation is intentionally sketchy.

+1

Having had over 30 years experience in the concept, design, development, fabrication, and deployment of high tech aerospace electronic systems where diplay technology is a trivial item and has been of only passing interest to me, I appreciate your insights.

Larry

Then I am sure you understand the problems that making assumptions about what vendors are doing can create...

I don't have a clue what you are talking about. I wish you had supplied a quoted reference.

Larry

Orta (or Dnice for that matter), i was wondering something. I am sure you know what ghosting is, or at least this is how i refer to it, when you have a bright image on the screen for a few moments then go to a completely black screen you can still see a very faint outline of the image, i guess this would technically be IR. I wonder if this is occuring on a much larger scale on these sets. I have been using the set for about 10 to 12 hrs straight today, kids watching tv, of course myself, plus a little hard core gaming, buy any case just a bit ago i decided to put up a completely black image, its one that is off of the break in images, and bam the black level is lighter again, i also poped in a bluray just to confirm, i tried the reset this time but still the same.

My question that im finally getting to is this, after having the set on so long, could the black level be lighter because of a residual charge built up just like ghosting, this time over the entire screen where i had been using the set all day with out a break. while i had the set on it stayed in thx mode. Im just trying to get a better understanding of what exactly is happening here. Im sure if my terminology is incorrect or my tech speak is off someone will be happy to jump in and correct it, but the general point still stands. could this be causing the black levels to appear lighter?????????????????