2407 and LCD banding issue revisited!

Question

Info pertaining to 2407’s and other LCD panels. Banding could be minimized through changes in firmware/software and other manufacturing, engineering and QC program changes. Adding Several 'dither options', that are noise filter algorithms, would allow the user to attempt to adjust the banding to a minimal nuisance level. Hence, the addition of the 'Soft Dither' option that now appears in the 2407 A03 factory menu. Whether Dell or BenQ will diligently peruse this option for these panels or for future products is up to them. This could help compensate for the minimal banding in Desktop and heavy banding in Multimedia and Gaming modes caused by the faulty Faroudja video processing ACC chip feature. More dither options = adjust banding to a minimum=better LCD panels=happier customers:) *ChrisM answered the following question from l_e_e pertaining to the 2007: l_e_e , 'would it be safe to say that the problem (banding) lies with Faroudja video processing ACC and that it’s a by-product of this so the problem is never going to be fixed.' ChrisM , * Correct. http://forums.us.dell.com/supportforums/board/message?board.id=dim_monitor&message.id=65302 At least ChrisM is being honest in relaying the information he has access to pertaining to the banding issue. Obviously this Faroudja video processing ACC chip was released before it was debugged and extensively tested in the lab. Time to market, rush to customers sometimes doesn’t work out so well. Like we all haven’t seen that before with software. Others and I have posted other reasons that also contribute to the banding issue of the manufacturing of LCD panels. Here is one of them: LCD panels and LCD projectors can manifest a problem known as vertical banding. LCD vertical banding is a flaw that can occur in the manufacturing process of the LCD panels themselves, and some LCD panels will tend to manifest it more noticeably than others. The panels that cause the most visible problems are usually weeded out in the vendor's quality control process. However, those that create just a hint of banding often pass through QC, since it is prohibitively expensive to discard all parts that exhibit flaws, which may have no practical impact on picture quality. So, we end up with a situation in which some LCD panels, even within a given production run on one model, will have no banding at all, some may have a hint of it that does not rise to the level of a significant issue, and some may have a more visible problem that really does impair the enjoyment of the viewing experience. In the latter case, sometimes the problem can be mitigated with internal adjustments made by the dealer or vendor service departments, and sometimes the LCD panels or the entire unit need to be replaced. Resolved: 1. Dell and suppliers should work towards providing consumer friendly adjustable LCD's so they can adjust these LCD's to eliminate or minimize the banding issues. Thanks to RadxGe, for the definitive proof (picture) of the hidden menu obvious firmware update in the A03's. A 'Soft Dither' option has been added to A03’s. This is an option that most likely has an impact on banding and noise. RadxGe has stated he has no banding in Desktop mode at all. RadxGe, confirm this statement. Some LCD panels offer several options, 'Dither Options', to eliminate banding or noise by utilizing various algorithmic noise filters for use in different LCD applications. And after all that, the Dell 24' 2407 is one of the best LCD panels on the market today. Features, jack panel (connectivity), price and an Advanced Exchange Warranty that can’t be beat. Some of the competitor’s panels I’ve seen have major hitches in games and flaws that are very disturbing and some panels on the market would be considered unusable. All comments welcome. Good Day to All:)

l_e_e · Answer

Hello, very interesting!!! but what i cant understand is that why did dell just turn off Faroudja video processing ACC chip feature in desktop mode? what does the feature do anyways. Another question i ask chris about but havent got an answer for yet is'what do the diff modes do anyways' If i just use the monitor in desktop mode with i see more ghosting? Maybe the different modes are there to speed up the pixels?
thx
lee

HRPretzel · Answer

I have a 2407wfp A02 (china) and 2407wfp A03 (mexico) sitting side by side.  Using DVI connections in Desktop mode with the display cloned (i.e. the same picture showing on each monitor).  The A02 has considerable vertical banding (horizontal steps) while the A03 has no banding at all.

all the facts · Answer

l_e_e,

Good questions, usually relates to profit margins, staffing and priorities when things are overlooked or complaints are ignored.

HRPretzel,

RadXGe posted a pic of an A02 and an A03 side by side and there is banding in the A02 and not in the A03 desktop mode only.

http://www.dropshots.com/day.php?userid=169814&cdate=20060828&ctime=140357

RadXGe also proved:
Yes, I do have an A03.
I confirm that the hidden factory OSD menu contains the option 'Soft Dither'. This option is set to "On(+)" by default.
This is interesting indeed...

url to pic http://forums.us.dell.com/supportforums/board/message?board.id=dim_monitor&message.id=65139

url to thread :

http://forums.us.dell.com/supportforums/board/message?board.id=dim_monitor&message.id=64097&query.id=178233#M64097

Good Day!

Smoothieboy · Answer

@HRPretzel wrote:

I have a 2407wfp A02 (china) and 2407wfp A03 (mexico) sitting side by side. Using DVI connections in Desktop mode with the display cloned (i.e. the same picture showing on each monitor). The A02 has considerable vertical banding (horizontal steps) while the A03 has no banding at all.

Glad to hear this. I'm returning my A02 to Dell and getting a replacement, which I hope is an A03. It should say on the box, so if it's an A02 it's going back to Dell unopened.

big face · Answer

Hi All   After much thinking about it and reading/ re-reading these forums Im finally going to go ahead and order the 2407.... or am I?... Im so indecisive!   I contacted a sales rep for NZ who was unable(unwilling?) to say what rev. are currently being shipped. In answer to my questions , the reply was...'I dont know what you mean by rev 02/03?' and 'you will get the latest product'.....Mind you, not sure what Ill do if it turns up with rev AO2 on the box.....accept or decline.....accept or decline.....   Ive never bought Dell before (Im also getting a new system) so hopefully the returns policy/procedure is good if things are faulty (I presume/hope if its faulty they pay for shipping/return costs??).... Ill probably get the 5yr Advanced Exchange so have plenty of time to get one that works ok ! :smileyhappy:   Cheers

gpro · Answer

lee,
ACC/ACM pdf explains display modes and their relationship to banding. My guess is that ACC/ACM was never meant to be enabled in Desktop mode. I don't think the modes affect response rate - just color & contrast presets.

Talkiet · Answer

@big face wrote:

Hi All

I contacted a sales rep for NZ who was unable(unwilling?) to say what rev. are currently being shipped.

In NZ you will absolutely, positively get an A02 if you order now, and there's a chance you'll get a refurbed A02 as well.

I currently have an A02 and have had 3 exchanges so far. I have come to an agreement with Dell that I won't exchange again until the A03's are available... The most current (1 week old) news I have is that they don't know if they will bring the A03 to AU/NZ at all.

If you can live with the minor banding, Fast SD cards not working, being unable to set 1:1 ratios, low resolution (720*576) not working, component inputs giving terrible quality, then it's a great monitor.

Personally I would have returned this for a refund already, but it was such a good deal when I bought it that I'd rather hold Dell to their obligation to provide a product that is up to the standards advertised.

Regards

all the facts · Answer

gpro wrote: 'ACC/ACM pdf explains display modes and their relationship to banding. My guess is that ACC/ACM was never meant to be enabled in Desktop mode. I don't think the modes affect response rate - just color & contrast presets.' Good Info., thanks again, Have you tried disabling ACC in the hidden menu? Do you think it will help with the banding? You would think BenQ would have tried everything we could possibly think of since they are involved in the engineering phase. Post back. Good Day:)

all the facts · Answer

Call of Duty One with a TI4600 at 1600x1200 banding in the sky with sun glare scenes.

Changed to 800x600 fuzzy text, doesn't look to good but, banding gone and some of the other eye candy with it, like no more sun glare, where sun glare was before but, no banding.

Someone posted elsewhere, we all are using outdated video cards like mine 4 years old and he was using a 7900 gtx and he had no banding. He blamed the banding complaints on the old cards. What do you all think about that? :)

Good Day!

Riffe · Answer

I've tried playing with ACC in the hidden menu to no avail. Banding is equally apparent in both modes (on/off).

Also, I've just received my replacement monitor, which unfortunately is an A02, ordered in Sweden. :( It's pretty much identical to my first monitor, except with perhaps a slightly more obvious banding and no tiny speck beneath the surface (no, not a dead/stuck pixel, just dirt or something).

Unless Dell can promise me that I can call them up and have my monitor replaced in say six months (or whenever the A03 has arrived in the great North), I'm returning both of the monitors and intend to wait. Prices won't go up. :)

-Riffe

all the facts · Answer

Riffe and all,

Thanks for trying the ACC, on and off, unfortunately with no luck.
Someone else tried toggling the "soft dither" option in the A03 hidden menu (because A02's don't have that option) and when turned off the banding did not come back. Well, that test really was not that necessary but had to be looked at and we now know the banding won't come back toggling it in an A03.:)

No answer yet, from ChrisM, for this question which has its very own thread.:
"ChrisM, When will 2407 A03's be shipping from all hubs in the U.S. and internationally?"
I'm sure everyone has seen it by now.:) Hopefully, Chris will get an answer soon and post it. Until we get a definite date, there is no promise of ever getting an A03 at any specific location in the world. I hope it's not a selective regional distribution, which would be unacceptable to loyal customers.
I could do Advanced Exchanges until I get A03's, but what a waste of time and money.

Riffe quote,
“Unless Dell can promise me that I can call them up and have my monitor replaced in say six months (or whenever the A03 has arrived in the great North), I'm returning both of the monitors and intend to wait. Prices won't go up.”

This is why Dell should get us that specific date A.S.A.P.

So for now, I'm going to use VGA, as I was able to totally eliminate banding in desktop mode from my A02's.
I corrected the bold text issue I had (adjusting pixel clock and phase) and it looks almost as good as DVI text now. Not using clear type and am not rounding text thru advanced performance settings in Win XP Pro. Now I can use the DVI with an HDMI converter (about $30.00U.S. so I've read here) if I had an HDMI source. I would like to get one in the future.

1. What Disadvantages does VGA have that DVI does not? What's the down side of VGA: It has a contrast setting:)
What else?

Here's the million-dollar questions.
2. Will the HDMI source, no matter what it is, Example: Standalone HDMI Blu-Ray player:), look bad because of the banding through the DVI input?. I would think so and that would totally ruin any HDMI source thru DVI.
HDMI compatibility was a big selling feature of the 2407.
3. But does anyone know for sure and what sources have you tried so far? Not, that it's a bad picture, like the 1080I complaints, but is it banding all over the screen like a PC source does in an A02. And I assume the 1080P Blu-Ray will down res. to 720P and not 480I. Are these assumptions correct?

4. Why does my current standard DVD player with 480P thru component input show up as 480I on the 2407, I thought the monitor supported 480P?

Thanks all,
GoodDay:)

Message Edited by all the facts on 09-20-2006 10:14 PM

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