An internal Apple memo on the iMac's yellow screen problem has been leaked by Gizmodo.
Apple has delayed shipments of the new 27-inch iMacs for three weeks which is assumed to be an attempt to fix manufacturing issues with the screen. It's also rumored that they will attempt to fix the flickering problem with a second patch thats expected in a few weeks.
Here's what the memo says:
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Symptoms
In certain combinations of lighting conditions and onscreen content, some customers may perceive very slight color variability on an iMac (27-inch, Late 2009) display. Some customers may report that certain areas of the display have a slight yellow tint.
Products Affected
iMac (27-inch, Late 2009)
Resolution
Do not attempt a repair or replacement at this time. Explain that slight color variability is normal for LCD displays and in general does not warrant replacement. Customers who are concerned that their iMac has a yellow tint issue, and who provide contact information, will be contacted by Apple in approximately 3 weeks to arrange a LCD panel replacement. Those who do not wish to provide contact information can contact Apple in the future for the latest information. Customers who require an immediate resolution should be offered a refund. Please transfer these customers to Customer Relations for handling.
Tier 1 Instructions
Calls should be logged under the follow Component and Issue to ensure that the customer will be contacted when a solution becomes available.
Component: System Video
Issue: Non uniform color or brightness
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Gizmodo also quotes a user who fixed originally fixed his iMac without knowing how he did it but who now thinks he may have figured out the issue:
I now am fairly certain that the yellowing of the display is a manufacturing defect involving the distance between a layer of material used to diffuse the LED backlight and the LCD panel. To show a perfectly even color, this light scattering panel has to be absolutely flat and free of any warping, kinking, or thickness defects. It is this layer that I believe is at fault, and causes the color to drift and give the perception of yellow stripes, fields, and corners.
This would be absolutely consistent with the reports of horizontal and vertical stripes (a vertical or horizontal kink) or corners (a bad tuck). I believe these defects may not appear in the factory. Rather, with the rough handling the monitors receive when shipped this layer gets knocked out of alignment.
I don't know what Apple could do to solve this problem, other than a wholesale change of manufacturer for the panels, or a complete redesign of the panels themselves to better pin the diffusion layer.
It also explains why my careful assembly and dis-assembly resulted in the yellowing disappearing. By being cautious, I basically returned the monitors to the original factory state of perfect alignment.
If you are wanting to buy a 27-inch iMac we should suggest waiting until these issues are resolved before making your purchase.
Read More
Apple has delayed shipments of the new 27-inch iMacs for three weeks which is assumed to be an attempt to fix manufacturing issues with the screen. It's also rumored that they will attempt to fix the flickering problem with a second patch thats expected in a few weeks.
Here's what the memo says:
-----
Symptoms
In certain combinations of lighting conditions and onscreen content, some customers may perceive very slight color variability on an iMac (27-inch, Late 2009) display. Some customers may report that certain areas of the display have a slight yellow tint.
Products Affected
iMac (27-inch, Late 2009)
Resolution
Do not attempt a repair or replacement at this time. Explain that slight color variability is normal for LCD displays and in general does not warrant replacement. Customers who are concerned that their iMac has a yellow tint issue, and who provide contact information, will be contacted by Apple in approximately 3 weeks to arrange a LCD panel replacement. Those who do not wish to provide contact information can contact Apple in the future for the latest information. Customers who require an immediate resolution should be offered a refund. Please transfer these customers to Customer Relations for handling.
Tier 1 Instructions
Calls should be logged under the follow Component and Issue to ensure that the customer will be contacted when a solution becomes available.
Component: System Video
Issue: Non uniform color or brightness
-----
Gizmodo also quotes a user who fixed originally fixed his iMac without knowing how he did it but who now thinks he may have figured out the issue:
I now am fairly certain that the yellowing of the display is a manufacturing defect involving the distance between a layer of material used to diffuse the LED backlight and the LCD panel. To show a perfectly even color, this light scattering panel has to be absolutely flat and free of any warping, kinking, or thickness defects. It is this layer that I believe is at fault, and causes the color to drift and give the perception of yellow stripes, fields, and corners.
This would be absolutely consistent with the reports of horizontal and vertical stripes (a vertical or horizontal kink) or corners (a bad tuck). I believe these defects may not appear in the factory. Rather, with the rough handling the monitors receive when shipped this layer gets knocked out of alignment.
I don't know what Apple could do to solve this problem, other than a wholesale change of manufacturer for the panels, or a complete redesign of the panels themselves to better pin the diffusion layer.
It also explains why my careful assembly and dis-assembly resulted in the yellowing disappearing. By being cautious, I basically returned the monitors to the original factory state of perfect alignment.
If you are wanting to buy a 27-inch iMac we should suggest waiting until these issues are resolved before making your purchase.
Read More