Apple document details guidelines for handling LCD pixel anomalies

More commonly referred to as dead pixels, pixel anomalies can often be discovered in LCD-based laptop screens and flat-panel monitors. And the larger the display, the more prone the product is to contain several pixel anomalies.

Like most computer manufacturers, Apple's LCD products sometimes ship with several of these imperfections, though rarely is the customer eligible for a product replacement.

A recently uncovered document has revealed some of the guidelines followed by Apple's internal customer service department when determining whether a customer's LCD panel may be suitable for repair or replacement.

While a final inspection reportedly takes into account the proximity of faulty pixels to one another as well as location, in general Apple deems 3 bright subpixels to be acceptable on LCD displays that ranges from 12.1 inches to 15.2 inches in size. Meanwhile, on a 17-inch to 20-inch LCD, the company finds 4 bright subpixels, 6 dark subpixels, or a combination of 8 bright and dark subpixels to be acceptable.

For the larger 22-inch and 23-inch Cinema displays, Apple guidelines list 10 dark subpixels or a combination of 15 bright and dark subpixels to be acceptable, but does not provide acceptability figures for bright subpixel counts on displays of this size.

Judging by the figures, it seems logical that some of the company's new 30-inch HD Cinema displays could ship with a combined 20 or so pixel anomalies, yet still be considered as an acceptable product.

To date, Apple pixel anomaly guidelines do not provide references to displays larger than 23 inches.