26 - PowerBook G4 (17-inch) Troubleshooting Hardware Symptom Charts
5. If the number of subpixel anomalies is acceptable, explain to the customer that the
pixel anomalies are within specifications, and no repair is necessary.
Important: Do not release the specifications to customers. Instead, inform them that a
certain number of subpixel anomalies are considered acceptable, and these factors apply
to all manufacturers using LCD technology—not just Apple products.
When speaking with customers, please use the following explanation:
Active-matrix LCD technology uses rows and columns of addressable locations (pixels)
that render text and images on screen. Each pixel location has three separate subpixels
(red, green, and blue) that allow the image to be rendered in full color. Each subpixel has a
corresponding transistor responsible for turning the subpixel on or off.
There are typically millions of these subpixels on an LCD display. For example, the LCD
panel used in the Apple Cinema HD display is made up of 2.3 million pixels and 6.9 million
red, green, and blue subpixels. Occasionally, a transistor does not work perfectly, which
may result in the affected subpixel being turned on (bright) or turned off (dark). With the
millions of subpixels on a display, it is quite possible to have a low number of faulty
transistors on an LCD. Therefore, a certain number of subpixel anomalies are considered
acceptable. Rejecting all but perfect LCD panels would significantly increase the retail
price for products using LCD displays. These factors apply to all manufacturers using LCD
technology—not just Apple products.
Hard Drive

Internal hard drive will not initialize:

1. Start up from the software install and restore disc that came with the computer (hold
down the "C" key during restart).
2. When the Installer opens, from the Installer menu, select Open Disk Utility.
3. If the hard drive is recognized, format it under the Erase tab.
4. If the hard drive is not recognized, reseat the hard drive flex cable, or replace if
needed.
5. If still not recognized, replace the hard drive.
6. Reinstall system software using the software install and restore disc.
Important: If the computer is under warranty and data recovery is required, refer to
Knowledge Base article 31077: DriveSavers: Hard Drive Data Recovery & Warranty
Implications, for important information.