Samsung 7 Series DLP White LED coating flaking over time?

No...suggest you learn how to use search correctly.

http://www.avsforum.com/avs-vb/showt...7#post15160407

Just wanted to add to this thread that this mysterious flaking issue is an completely unsubstantiated claim which Luminous (maker of the PhlatLight LED system found in the Samsung LED sets) denies.

I had a series of exchanges with Matt Mazzuchi a General Manager at Luminus who confirmed a few things for us:

1. The PhlatLight system assembly used in the Samsung sets is built for Samsung by Luminous. So if such a coating existed, Luminous would be the company to ask... So I did (see #2 below)

2. Luminous DOES NOT coat the LEDs with anything to achieve 6500k/D65 on the PT120 based chipset systems (found in the xA750 Samsungs) or on any of their LED products. To quote Matt "...Nothing flakes off the LEDs".

3. Off topic, but worth noting: The PT120 based chipset assembly used in the Samsung xA750 sets are used for multiple applications and will continue to be manufactered even after Samsung stops producing LED DLPs in 2009. So for those worried about replacement parts, at least the LED components will still be available for the foreseeable future.

So this information about the Samsung LEDs being prone to color problems down the road due to flaking is being denied altogether by Luminous and there is NOTHING to substantiate that they would be lieing about this. I would also like to add: generally in these sort of scenarios, if there is a problem the company remains silent and service techs certainly won't be so prompt to answer such questions, especially direct to the general public (I am no one of significance in this case, just an inquisitive consumer who asked a direct question)

NOTE TO MODERATORS: Is there anything that can be done to penalize those who post erroneous, unsubstantiated information? This sort of information (especially coming from someone waving their 'I'm a service tech' badge) is not only misleading, it's potentially damaging to the innocent technology companies involved. I just think those who post here should be more responsible and something should be done when they are called out on it. I understand there are a lot of strong opinions about certain makers and their build quality, etc... but I think these sort of post cross the line.

It's sure looking like a few people including some "calibrators" are posting less than accurate information.

These so called calibrators are nothing more than just slimy marketers/salesman trying desperately to raise their quota by attempting this scheme designed to eventually sucker you into buying their product from their store along with an extended warranty.

Samsung has been in the TV game a long time, they have a reputation that now rivals Sony for quality and features. This TV is extremely popular and has received glowing reviews across the board. Go to Amazon - 4 1/2 starts out of 5 by hundreds of people. Go to Cnet - Editor's Choice Award

Rated 10th best out of all the massively more expensive similar sized TVs on the current market. No other DLP came close.

Now That's quantitative information.

As I said in an earlier post Luminous has said there is no coating on the LEDs used in the Samsung LED DLPS. I believe this rumor got its start with this article (written in 2007)

http://www2.electronicproducts.com/L...2007-html.aspx

The article is discussing LEDs and mentions two methods of producing white. One of those methods involves using a phosphor coating, the other does not. The method described that does not use the coating is consistent with the approach Luminous describes for the PT120 chipset:

http://www.luminus.com/content1092

This comes as no surprise, unsubstantiated rumors are all over the place about everything. Even the smartest people can be conned into believing something that isn't so if they accept the argument as mistaken fact instead of going to the source to confirm it as actual fact before repeating what they're being told to others. I know because I've been guilty of it in the past. I think everyone has to a certain extent.

Unfortunately, such rumors have put honest companies out of business. It has even happened in my own family. Does the name Preston Tucker ring any bells??? That's going back about 61 years though ...

I've had a 61A750 since March 2008 which currently has 3942 LED hours. During that time I have recalibrated it several times (for my own amusement) using a I1 PRO, Calman V2 & V3, Getgray disk. All of these times there have been no significant differences in the settings and those were probably due to the I1 location on the screen. Certainly if degradation was going to happen there would have been some change in 4000 hours!

Just curious - how do I find the hours used? I don't recall seeing that anywhere in the threads. Sorry for this being off-topic.

It's in the Service Menu/Option Byte/LED Life. Right above is option to clear LED timer if you wish.

Pretty lame. You offer a snide reply that the OP can't use the search and your proffered thread says absolutely zero about a coating flaking. After some www research I feel comfortable with the fact their is no coating. If you have some proof poney it up, if not I would suppose logical minds will come to the conclusion that you are mearly supporting rumor.

Then you do not know anything about LEDs achieve color and the doping process.

First, please don't make blanket statements about calibrators. All calibrators are not created equal. Second, you're confusing calibrators with big box stores that want to sell warranties. Calibrators don't sell warranties. They just calibrate.

What I think is funny is I do indeed understand it, obviously better than you because you keep mixing up doping and phospher coatings. Doping is when you create the p-n junction INSIDE the LED by impurities being added to the semiconductor this sets up a senario so that when an electron hits a hole it drops a valance level and releases a photon. Doping has NOTHING to do with the outside of an LED and is on an atomic level not exactly something that "flakes". It is obvious you got the incorrectly used term of art "doping" from the thread with the "pro calibrators" posting to it, you using it incorrectly just clarifies the fact you are a parrot and don't have any real idea what you are foaming about. Remember this doping is NOT like doping a model airplane...


I just don't see any evidence for a coating that could actually "flake" which would idicate to me that it would be on the outside of the epoxy case. What you probably are referring to is phospher coating (such as YAG) to create "white" LEDs. Doping DOES come into this area of White LEDs as doped phospers such as Cerium doped YAG etc are used in certain white LEDs. But again this is on an atomic level and again inside the epoxy case for all white LEDs I am knowledable about. Now, I do concede PhlatLight LEDs are much different from LEDs I usually work with and thus could have different issues so if you have some proof of a coating used on them that could flake please illuminate us.


The potential issue with "white" LEDs, along with the normal LED failure modes would be differentiated phosphor degeneration. This would indeed cause the colors to shift over time.



What it comes down to is put up or shut up. Where is the proof that this exists. I will even accept anecdotal evidence IF the is a significant amount of it. So far you seem to be very coy with your proof, in most situations it means you have none. I am not going to further engage you on this topic, unless you produce significant credible evidence and then I will aknowledge it.



As for the entire white LED issue seems sorta a funny red herring since last time I checked the Phlatlight PT-120 chipset doesn't have a white LED in it... As for this mysterious white coating my guess it is like Nessie only a few claim to have seen, the majority will never see the myth.

I will admit I have not dealt with QDs but I didn't know that had any external coatings on the epoxy case either. It is a nanotech. In LEDs it allows the semiconductor crystals to be at or near Exciton Bohr Radius which gives you the ability to manipulate the bandgap from conduction to valence and therefore adjust the color without any need for phosphers or colored epoxy (ala some purple LEDs). There is a lot of tech there but I just have a basic understanding of it.


I am still lost with BEACH, normally red, green nor blue (unless you count sub 400nm which is not near primary blue) don't have any phosphors and doping is on a atomic level. Further the PhlatLight LEDs don't even have an epoxy case, do they? I thought they emmited into the air not covered by epoxy so I don't know where the coating could be, but best I can tell it ain't on the LED.

It really is comical and predictable.

The fanboys get angry and go into a rage when they hear there is a problem with the set they have.

Its the same in the Sony SXRD XBR1, XBR2, A2000 threads, now the SXRD A3000 threads, the Mitusbishi DLP threads....I could go on and on. The Company denies there is any problem.

Denial and lines in the sand are drawn, mostly using the "shoot the messenger" attitude.

Then the problem becomes more and more known.

A few continue to claim the previous posters are idiots.

Then more and more find the issue.

Then there is a change in warranty status by the Company (at least the legit ones) as there is no escaping the reality of the issue.

In many of the extreme cases mentioned above, they start switching out sets to a newer model, claiming they have fixed the problem part in the new models....only to find out 18-24 months later the part was never fixed.

And then there are the Class Action suits which complete the cycle.

You guys are just at the beginning of a long adventure that is documented in MANY threads on many different models in this section. I'll be sure to bookmark this thread an post a big HA HA when your denial is no longer an option.


Nope, because they are smart enough to know the threads and these are the steps that all the defects/threads go through.


Lots of luck with that as the i1 Pro and other cheaper meters will not be able to properly read the spectral energy of LEDs (or lasers). They are not built for that.

While that may be true a consistent reading is a consistent reading accurate or not. The visual results approximate the best I've seen and I'm ignorantly happy.

Like an angry former governor of Illinois you can't seem to accept when you've been shamed.... Listen, I'm not a fanboy, but I do get angry when I read a lot of misleading information (here) under the guise of being 'from a professional' and I do some digging and find that information is being mis-interpreted through biased filters.

I'm not going to change the way you view this, I don't intend to try... I'm not sure what has given you the opinion you hold of this technology since there is no first hand experience and the second hand information you did provide was relatively old, weak (given your claim) and overall very unconvincing given the enormous amount of positive information in the counter argument.

I'm just trying to provide more information to add to the counter argument which I think for those who investigate this for themselves will find is much, much stronger than what you have provided.

I'm not sure 'fanboy' is the proper term, but there does seem to be an anger in the subtext of your post in this thread and elsewhere about LED DLP technology in general. Can you tell us about that? Sharing a first hand experience of how Samsung or LED DLP technology in general had a negative effect on you (or your customers) would probably serve your cause better than venturing up this tree.

Beach, I don't see myself as a fanboy, though that is a label applied from the outside. I do like the a750 sets and recommend them though I always list the caveats that I am aware of, namely size, potential geometry issues and viewing angle. If there is another serious potential issue I would gladly add "coating flaking" as another one.

There may be a deeper history to this thread on this forum than I am aware of. Understand I honestly want to understand the mode and potential for this failure. I influence a number of AV purchases a year and would like them to be as accurate as possible, all I am asking you to do is provide the information you have so I can consider the issue myself. To this point I have no idea why you would not share it. The only information you have provided in this thread was a thread that simply said LED light engines can color drift over time and the poster mentions that so do the majority of other technologies. I have searched the web for ANY evidence of any coating on a PhlatLight PT120 flaking off. I can accept my search abilities are not perfect, just show me where I am missing it.

I just don't understand why you refuse to offer any evidence, anecdotal or otherwise.

That's because they don't 'flake' there is no coating applied to the LEDs found in the Samsung DLP HDTVs. The source of this rumor seems to be article from 2006 which describes two methods for LEDs to produce white, one of those involved phosphor coating the other did not. My source on this is the manufactuer of the product PhlatLight LEDs, Luminous.


The color drifting issue is valid and something interesting about this technology we did learn... It's also possible this color drift issue (as described in 2006) has been greatly reduced by new techniques developed by Luminous (someone else mentioned color balancing techology that prevents drifting in these sets without provuding any technical details... anyone have info on this?) Triple gun CRTs do the same thing, but even if we got half of the life expectancy (30,000) out of one of these sets that's roughly 15 years of use. It's sort of like 'surpise, suprise' LED isn't indestructible and is a degrading technology just like anything. The time frame for the drift is what we're interested in. If it becomes a issue around 10,000 hours that's quite a bit more of a concern that if it reveals itself around 30,000-60,000 hours. Since the LEDs themselves are rated at 100,000 is Samsung taking into account the color drift when they rate the X700 series televisions at 60,000 hours? All good questions. If we could get someone knowledgable (unlike BeachComber) to give us answers that would be great.

Nice positive contribution to the forums there.

All this time and the huge 750 series threads and only one poster that talks about Samsung's version of the Loch Ness Monster without the ability to link to even a shread of anecdotal evidence other than his/her own. (sarcasm on) Count me completely conviced this rumor is true...(sarcasm off).

The sets have their issues (as all do) but it certainly doesn't seem to be this white flakes.

Here is the latest response I received from luminus:

There are no phosphors in our devices, thus negating claims as described. *We just use separate red, green and blue LEDs to get the color desired, and Samsung deals with the color balance and combination aspects. *LEDs do move a bit over time, but long term aging tests do show very stable performance. **We cannot comment on the TV set details as we do not have expertise in this area.

They told me the same thing.... anyone can contact Luminous and they will respond with this information, this isn't some concpriousy they are pretty up front that it's a non-issue created by rumor.

As I referenced before there was a technical article published circa 2006 (prior to the first LED DLP sets coming to market) that discussed two possibilities for LED based displays to generate white, one of the methods involved using a prospher coating the other did not... The LEDs made by Luminous DO NOT use this approach... I do believe this article was the source of the phosphor coating rumor. What is quite interesting is how we get 'first hand accounts' of white specs that supposedly are directly tied to this phospher coating that doesn't exist.... (Take everything you read here with a grain of salt unless it can be substantiated). The truth seems to be that the LED based sets upset techs because it's sort of it's own monster to service/repair.... what you don't understand you try to make sense of and sometimes that just doesn't work, even for competent people.

One last observation: the LED set used in the xA750 line is rated for (up to) 100,000 life span. Samsung has chosen to rate their xA750 line at 60,000. Why the 40% drop? I asked Samsung this question and did not get a reply, but one possibility is they are accounting for color shift beginning after 60,000 hours... People tend to forget Samsung and SONY operate solid R&D labs, they didn't become established brand names putting out mediocre products.