27in iMac screen flicker issue fixed - or not?

Stephen Withers
Tuesday, 22 December 2009 08:44

Opinion and Analysis

The 27in iMac is a fine looking machine, but some owners have been complaining about screen flicker. Apple reckons it's found the answer.

One of the more common complaints among dissatisfied 27in iMac owners has been display flickering and other anomalies.

Apple has now released a firmware update to cure the flickering.

According to Apple, "The 27-inch iMac Graphics Firmware Update applies to the graphics firmware on ATI Radeon HD 4670 and 4850 graphics cards to address issues that may cause image corruption or the display to flicker."

But if messages posted on Apple's own discussion forums are anything to go by, the update isn't a 100% cure. Some purported owners claimed that the flicker persisted after the update was applied.

Others say the flickering was an intermittent problem and that they are as yet unable to tell whether the update has done its job.

Apple's advice is that "If your screen remains black after applying the updater or if you continue to experience image corruption or display flickering after successfully completing this update, contact AppleCare or an Apple Authorized Service Provider."

Several customers report that Apple is either swapping their affected iMacs for brand new ones, or replacing the display panels.

Another widely reported issue - also affecting the 21.5in model - concerns a yellow tinge affecting parts of the screen, most commonly the lower section. Judging by owner reports, this is a hardware issue unrelated to the matters addressed by the firmware update.