Apple released a new firmware update today to address issues that may cause display flickering on the company's 27-inch iMac.
Updates the display firmware on 27-inch iMac systems to address issues that may cause intermittent display flickering.
The 27-inch iMac Display Update will update the display firmware on your iMac. Do not disturb or shut off the power on your iMac during this update.
This firmware update appears to address the display hardware itself. The 27-inch iMac Display Update Firmware is 294KB in size. You can download the update from the following link: http://support.apple.com/kb/DL998 and installation instructions are located here: http://support.apple.com/kb/TS3207
[...] has released two display updates to attempt and address the issues. It seems like the second one helped many users with screen [...]