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Discussion Starter · #1 ·
So it's been confirmed that the rising black levels in 2009 Panasonic plasmas is due to a voltage change in the set. It's also been reported that when this voltage change occurs and black levels rise, image retention seems to get worse as well. Interestingly, Samsung's by comparison are known to have poorer black levels and worse image retention than a freshly-broken Panasonic from the getgo. So, they must be operating at a higher voltage by design, yes? And Pioneer's are known for not only excellent black levels but also next to no image retention. Probably also related to voltage, right? And dithering seems to work in reverse; the tvs with the worst black levels and image retention (samsung) are known to have the least amount of dithering, followed by Panasonic and then Pioneer. So perhaps dithering is also related to voltage.


Assuming all of that is true, my next question is what can affect voltage beyond what the internal programming of the television is telling it to do? Power supplies? Room temperature? Line conditioners? Surge protectors? The quality of your outlets? I question because it's no secret that black level performance and image retention seems to vary greatly on even the same television; one owner will claim to have no noticeable image retention while another says it lasts for hours (both after 100s of hours on their sets). And black level measurements also vary greatly on the same model televisions. I wonder too if voltage could be part of what makes some '09 Samsung's buzz and some not, and if there would be notable picture differences between a buzzer and a non-buzzer.


Thoughts?
 

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I know Pioneers use more power than the others. If I have my KRP500 in Standard mode, it uses ~300W variable. Save 2 pushes it down to mid 100's. If I had to guess I'd say the ones using lower wattage/brightness either are doing something funny with amplifying the power (Pioneer seems to just use the flat power in comparison and doing less amp'ing if any) and/or are using phosphors that require less power to drive. If they require less power to drive, they may be more transient/volatile and hence more prone to IR (getting stuck in one state) or to changes in voltage over time (black level increase). Alternatively, it could be that the Pioneer's were simply manufactured on a smaller scale and thence to a higher degree of quality so voltage is either more tightly controlled and/or the panels are all much closer to design spec.


Regarding power, this ones very important. You should have a powerbackup and line conditioner for your tv. Most people do. House power can play a big role if you don't have proper equipment hooked up. I would not hook up a tv to a standard surge protector. You want one with line conditioning and a battery backup somewhere in the chain is a good idea. That said, I'm pretty sure a bunch of people with the rising black levels have all those and more since they're videophiles and very particular about their setups. These issues seem to be happening due to the nature of the sets more than any power being supplies to them.
 

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Based on this logic, I'd wonder if dithering clears up/improves as black levels rise.
 

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Just a couple of notes: According to D-Nice, the initialization voltage can be raised without having the black level rise. If this is the case then it's not just a matter of a voltage increase because you'd notice a worsening of black levels on all plasmas then, not just Panasonic's (assuming that they too have a scheduled voltage rise to prevent pixel misfiring). There is something else going on with the Panasonics it seems...don't know what exactly.


Also, some people have solved the buzzing issue by tightening the fan screws as it turned out this was the culprit (my cable box buzzes loudly until I push one side of it indicating it is a mechanical noise, not electrical). These could be the exceptions though rather than the rule.


These are just some theories but since Panasonic won't share any info (trade secrets) we may never know.
 

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Quote:
Originally Posted by dlplover /forum/post/18147008


I know Pioneers use more power than the others. If I have my KRP500 in Standard mode, it uses ~300W variable. Save 2 pushes it down to mid 100's. If I had to guess I'd say the ones using lower wattage/brightness either are doing something funny with amplifying the power (Pioneer seems to just use the flat power in comparison and doing less amp'ing if any) and/or are using phosphors that require less power to drive. If they require less power to drive, they may be more transient/volatile and hence more prone to IR (getting stuck in one state) or to changes in voltage over time (black level increase). Alternatively, it could be that the Pioneer's were simply manufactured on a smaller scale and thence to a higher degree of quality so voltage is either more tightly controlled and/or the panels are all much closer to design spec.


Regarding power, this ones very important. You should have a powerbackup and line conditioner for your tv. Most people do. House power can play a big role if you don't have proper equipment hooked up. I would not hook up a tv to a standard surge protector. You want one with line conditioning and a battery backup somewhere in the chain is a good idea. That said, I'm pretty sure a bunch of people with the rising black levels have all those and more since they're videophiles and very particular about their setups. These issues seem to be happening due to the nature of the sets more than any power being supplies to them.

what kind of surge protector has a line conditioner and powerbackup in it?
 

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I don't think incoming voltage would play any part in the issues you are talking about. Incoming power is regulated, probably more than once, down to a usable voltage. The internal regulators/power supplies would convert the incoming ac(aprox 100-140 volts ac) down to something like 5-24volts dc for the control boards to operate on.


Forgive if I don't have exact internal voltages correct, I'm basing my opinion on the equipment I work with (very large rectifiers, power supplies and battery chargers.)


That said I do use a basic power conditioner/surge protector for noise and lightning issues(Newpoint Theater Director).
 

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...again, where would i find such a thing? this super surge protector stuff is all still french to me
 

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Quote:
Originally Posted by kagolu /forum/post/18148712


I don't think incoming voltage would play any part in the issues you are talking about. Incoming power is regulated, probably more than once, down to a usable voltage. The internal regulators/power supplies would convert the incoming ac(aprox 100-140 volts ac) down to something like 5-24volts dc for the control boards to operate on.

exactly. any external change (like a surge protector) is irrelevant. we are talking about INTERNAL voltages after it has already been passed through and regulated by the power supply.


it's not a light bulb on a dimmer switch
 

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All depends how much you want to spend. Just make sure it has line conditioning. The more expensive ones typically will do a better job.

http://www.amazon.com/APC-SUA750-6-O...6360556&sr=8-2 (this one might not - you'd have to check)
http://www.amazon.com/Tripp-Lite-SMA...360696&sr=8-16
http://www.amazon.com/APC-SUA3000XL-...6360556&sr=8-6
http://www.amazon.com/Tripp-Lite-SU1...6360556&sr=8-5


You can also do it on a budget as separates... just get a UPS that can handle the wattage you need and run the line conditioner off that.
 

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holy crap those are expensive. I couldnt justify spending 6k on a surge thingy when i only spend 1.5k on the tv
 

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Quote:
Originally Posted by batpig /forum/post/18148853


exactly. any external change (like a surge protector) is irrelevant. we are talking about INTERNAL voltages after it has already been passed through and regulated by the power supply.


it's not a light bulb on a dimmer switch

Well there's a lot of electronics in there that can get fried, but regardless I agree with you that the black level rise is unlikely to have anything to do with voltage input assuming it's on any device with nominal voltage regulation/line conditioning.
 

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Quote:
Originally Posted by SIRL0INofBEEF /forum/post/18148886


holy crap those are expensive. I couldnt justify spending 6k on a surge thingy when i only spend 1.5k on the tv

You asked and I delivered



Even cheap UPS's these days will typically have some line conditioning. I was just demonstrating that you can go as crazy as you want on it (and I'm sure people do)... Better ones have cleaner line conditioning... how much benefit you get vs. what you pay is a different question. My take is that as long as you have some basic line conditioning you are probably ok. The line conditioning build into the cheaper UPS units won't be as good as a UPS unit + dedicated line conditioner (both relatively cheap on their own). Getting something that does both well is likely to cost more. I'm happy with my UPS for my Kuro and haven't had any ill effects for not spending hundreds or thousands on fancy ones. Some people do and swear by them so I won't naysay if someone wants to.
 

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Discussion Starter · #15 ·

Quote:
Originally Posted by kagolu /forum/post/18148712


I don't think incoming voltage would play any part in the issues you are talking about. Incoming power is regulated, probably more than once, down to a usable voltage. The internal regulators/power supplies would convert the incoming ac(aprox 100-140 volts ac) down to something like 5-24volts dc for the control boards to operate on.


Forgive if I don't have exact internal voltages correct, I'm basing my opinion on the equipment I work with (very large rectifiers, power supplies and battery chargers.)


That said I do use a basic power conditioner/surge protector for noise and lightning issues(Newpoint Theater Director).

So, theoretically then people shouldn't see inconsistent picture performance between the same model televisions due to their environments affecting voltage/power?
 

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I thought the driving voltage adjustments were to maintain brightness as the phosphors age??? if so, why not tie the driving voltage to the picture mode... run higher voltages with 'vivid' and leave it alone (albeit with decreasing brightness over time) in the other modes. Having said that, how do the 'brightness' or 'black level' settings impact brightness and black level without touching the drive voltage, respectively, and is there any reason the drive voltage cannot be in a menu?
 

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No external voltage is going to affect the set unless it's outside the range power supply for the set is designed to handle.


As to why different sets of the same year model have different measurable black levels. That just has to do with level of accuracy and precision that every resistor, capacitor, inductor, transistor etc... is built to. You would have to expect that not every single one of those components is going to have exact the exact same resistance, capacitance, or inductance. The sum of all those individual differences is what creates those differences you see in the different sets.


As for buzzing, rising black levels, dithering etc. These are probably just different because of inherent design differences between manufacturers.
 

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Quote:
Originally Posted by dougri /forum/post/18158814


I thought the driving voltage adjustments were to maintain brightness as the phosphors age???

NO. this is probably the most out-of-control misconception about the issue that is out there. It has nothing to do with keeping plasmas "bright" to counteract the supposed dimming as they age. It's only about regulating the initializing voltage that fires the cell as the reactivity of the gas in the cells changes over time. There have been many good explanations posted in the master "black level" thread.
 

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Discussion Starter · #19 ·

Quote:
Originally Posted by batpig /forum/post/18160600


NO. this is probably the most out-of-control misconception about the issue that is out there. It has nothing to do with keeping plasmas "bright" to counteract the supposed dimming as they age. It's only about regulating the initializing voltage that fires the cell as the reactivity of the gas in the cells changes over time. There have been many good explanations posted in the master "black level" thread.

What is the outcome of increased voltage? I know they say it keeps the phosphors from "misfiring", but what does that translate to in terms of picture? I've presumed, perhaps incorrectly, that misfiring phosphors would lead to a dirty, inaccurate picture.
 

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Quote:
Originally Posted by Spanbauer /forum/post/18161018


What is the outcome of increased voltage? I know they say it keeps the phosphors from "misfiring", but what does that translate to in terms of picture? I've presumed, perhaps incorrectly, that misfiring phosphors would lead to a dirty, inaccurate picture.

This black level/voltage issue does not involve the phosphor or the lifetime of the display. It mainly concerns the strength of discharge (ionization) of the Xenon/Neon gases inside the pixels.


Please see the following post describing the issue.

http://www.avsforum.com/avs-vb/showt...3#post17831713


Cheers
 
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