Q: New iMac 27inch screen flickering/tearing/shutoff

Check out the Toyota fiasco for a textbook illustration of what goes wrong when a company does not get out in front of a known issue. No known fatalities involved with the new Apple computers, of course (unless someone has jumped off a bridge in frustration), but the idea is the same: a lack of action resulting in a severely dented reputation.

http://www.nytimes.com/2010/02/01/business/01toyota.html?hpw

Jacques LAPORTE wrote:
Salut Nexus600,

Very good post yesterday.

I have done research on the backlighting used (model LM270WQ1 from LG).

In the IMac 27" (or 21" Dino ...), the backlight is produced by *white LEDs* and though I have no further details (and have not yet dismantled one - as 'ifixit' did) it is clear, in my opinion, that a backlight diffuser is used to ensure even lightning and that this diffuser must be perfectly parallel to the LCD panel.

It is just a clue to investigate for the "yellow" tint default, but the spatial alignment of the diffuser bend in relation to the LCD panel is critical. How is it fixed to the rest of the panel. Could it be moved by a bump?

Realignment by software .... hum??

I was told that a *RGB LED backlight technology* -that would allow to correct the temp of white -would make the screen over 3000$

All this to be confirmed.

Cheers.

Jacques,



I think misalignment of the diffuser is a plausible cause for the yellowing.

Realignment by software? I don't see how that could be done.

As for RGB LED technology, that's imposible to do.

In LCDs screens each pixel is divided in 3 subpixels with red,blue and green filters.Different shades of each colors are created by controlling the voltage applied to the subpixels.

So basically, the color is done by the LCD and not by the LED.
The LED only provides the light source to illuminate the LCD.

To have an RGB LED screen you would need to have LEDs small enough to create the 3 subpixels mentioned above.

That's LEDs that would be 1/3 of a pixel in size.
To my knowledge, this does not exist.

LED screens are the ones you see in Time square or at football and hockey games.
In these screen, each pixel is big enough to be able to use 3 LEDs to create RGB subpixels.

Message was edited by: Nexus600

John Sierputowski wrote:
Apple seems to stop iMac production...

http://www.hardmac.com/news/2010/02/01/production-of-all-imac-27-core-ix-models- stopped-by-apple

Seems highly unlikely that Apple would continue to show ship times of 3 weeks if this were true, although I hope it is true!

tattoo99 wrote:

Seems highly unlikely that Apple would continue to show ship times of 3 weeks if this were true, although I hope it is true!

That would mean that the never ending story could take a way towards the solution.
This problem has been known since November, I think it's enough. It's rediculous that thousand people continue to buy a product having a clear problem.

No tattoo....... the article is not true.

There have been a few posts on this thread from users who have received week 02 and 03 machines.

FedEx tried to deliver my replacement machine about an hour ago, but I wasn't here to receive it, (it was scheduled for delivery on Feb 3) hopefully it will be a week 04.

Obviously Apple has not suspended deliveries, and there is a good reason why the article does not provide it's source, it's simply not true.

Apple has stated that it has had difficulties acquiring enough 3.5 drives, and DRAM for the new models, and it has slowed production, and deliveries, but obviously, it has not stopped them.

Demand is greater than Apple's ability to supply, it even affects the refurbs, on the rare occasion when you do see any of the 27" models listed in the refurb store, they are gone in minutes.

... hopefully it will be a week 04.

pazuita, we have not one report from a week 04, although we already have February. Is there anybody out there having a week 04? It would be interesting to know.

pazuita, are you going to the FedEx office to pick it up? I'd be curious to know what Week Number you received & what the final verdict is. Good Luck! Hope you get a perfect one.

I just want to correct something I said in my last post.

Jacques Laporte was talking about RGB backlighting technology.

I miss read is comment and thought he was talking about an RGB LED based display technology.
I said that to my knowledge, it does not exist.

RGB backlighting technology does exist.
It uses RGB LEDs as the light source to illuminate an LCD display..

This results in a much greater range of possibilities in terms of color adjustments and calibration.If that was what was behind our iMac's LCDs we might have been able to correct the yellowing, but it's not the case.

It's still an LCD display but with a color adjustable backlighting system.

What to my knowledge does not exist, is a RGB LED based display in the sizes used in computers and laptops monitors .

I'll have to wait until tomorrow. Local FedEx isn't as flexible as some.

They have to make three delivery attempts before they return it to a holding facility where it can be picked up.

I should know the week number by noon tomorrow, central time. It could still be a week 03, but hoping for 04.......it just extends the warranty a little.

Maybe I jumped the gun a little.

The article stating that Apple has stopped production is dated 01/02/2010.

I would read that as January 2, 2010. If that is the case, the article is obviously nothing more than organic fertilizer.

Some might read it as February 01, 2010. In that case, it may still be possible, and any stoppage would not affect any units in transit, such as mine.

I would expect that Apple would extend the delivery dates ever further if indeed there was a stoppage.

Citrus......I don't think I've seen a week 04 listed here yet, but that week has just closed out, and since the defect rate in weeks 01, 02, and 03 have fallen so much, it is possible that there are so few in week 04 that if any are defective, there may be few, if any posters here with those models.

I, too, think the article is suspect (nothing substantiating it) but it doesn't seem entirely unreasonable given the leaked internal memo (Gizmodo: http://gizmodo.com/5459384/the-faulty-imac-saga-chapter-3-we-have-your-internal- memo-apple) that said that they'll be replacing LCD panels within the next 3 weeks. If they're changing how they build the LCD panels, it makes sense to stop the assembly line while they make changes to the panel process.

Also, note that it doesn't say they've stopped shipments (might as well ship out the models already in the pipeline). It says they've stopped new production. My next i7 was just delivered today; now I wish I had waited a little longer to order but we'll see tonight what week it is & how it performs...

Back after a week traveling. My 27" replacement machine (week 03) works fine (received Jan. 20, in use for 6 days, interruption one week).

I had a phone call with the Apple Store (Italy) today. I asked, if the screen problems are resolved and if I could order an iMac 27" now. He was polite and professional, but he did not really answer my question. He said that I can order now, I will get the machine in three weeks and I can be sure that Apple would not give me a faulty machine. He avoided to speak about the issues saying that I will get a new, functioning iMac.

He avoided to speak about the issues and he said nothing about a new fix, but the most interesting thing is, that he said nothing about a production-stop. I think, if there would be an official production-stop, he had to inform me. So I'm little bit doubtful about this new article.

Well, after my phone call it's clear, what I have to do. I have to wait and I swear I wanted to order this computer Nov. 09, because I wanted to have it under my Christmas-tree. My hole family can give evidence. They say, I should give up, but I do nottttt.

Brian_1338 wrote:
.... If they're changing how they build the LCD panels, it makes sense to stop the assembly line while they make changes to the panel process.

Exactly, production stop doesn't mean a shipment stop... iMacs already built must be shipped. Hold them in warehouse is a cost.