The complaints come at a time when Apple is apologizing for production delays, which it attributes to too many orders, without addressing the display issues.

Going Black

Writing on the Apple Discussions forum, Jan Sampermans of Belgium reported that his screen will go "completely black for a second and then come back on. Sometimes two to three times in a row." He added that in the course of writing his post, his screen has "flickered 13 times and has gone black two times."

Published reports document a wide variety of complaints about the 27-inch iMacs, including the flickering displays, as well as processor troubles and unbootable computers, cracked screens and yellow screens, noisy screens, and dead pixels.

Screen Test

Another user on Apple Discussions suggested those experiencing the problem connect an input source and use the screen only as a display to determine if the problem lies in the screen or in the processor.

Apple didn't immediately respond to our e-mail inquiry about the iMac problems.

But Michael Gartenberg, a vice president at Interpret, said he doubts the screen troubles will have much impact.

"There are always going to be technical problems with any new product," said Gartenberg. "The question is how they deal with it, and Apple has been historically very good at keeping customers happy."

Apple offers the new iMacs with a choice of a 3.33-GHz Intel Core 2 Duo processor or a 2.8-GHz Intel Core i7 quad core. The Cupertino, Calif.-based company announced in October that the quad core would ship later because of delays receiving hardware from Shanghai.

Apple also offers a 21.5-inch iMac which has not been reported to have problems.

Selling Fast

Starting at $1,199, the new Mac line features LED-backlit displays with edge-to-edge glass design and an aluminum enclosure. Apple boasts that with Intel Core 2 Duo processors starting at 3.06 GHz and Core i5 and i7 quad-core processors, they are the fastest Macs ever. Each unit is sold with a wireless keyboard and Magic Mouse.

Before the new Mac launch, Apple announced that it sold 3.05 million computers during the quarter ended Sept. 29, a 17 percent increase over the same quarter in 2008.

Even with the display problems, Mac sales this quarter are expected to rise 14 percent from last year.

Next year Apple reportedly expects revenue in the range of $11.3 billion to $11.6 billion in its first fiscal quarter.