Apple has quietly posted a "brightness update" for owners of iMac (Mid-2010) computers, aiming to fix an issue that is yet to be identified.
Customers have been complaining of a whistling sound coming from their iMacs, a problem that may have been addressed by this particular software update.
However, with the release of “iMac (Mid 2010) Display Brightness Update 1.0,” Apple claims it is addressing “an issue with 21.5-inch iMac (Mid 2010) display brightness.”
Apple Discussions forum users are saying their 21.5-inch iMacs are suffering from other problems that are related to the brightness level of their screens.
Owners of this particular iMac model are noting that they're hearing a high-pitched noise when brightness is set on high.
One forum poster claims he has been hearing the noise in pretty much every brightness level, except for the lowest.
“I bought one of the brand new iMacs this week and I've also got the high-pitched noise level in every brightness setting except the lowest under Mac OS X,” Durnaurion writes on Apple Discussions.
“When I boot Windows via Bootcamp though, I don't hear the sound when the brightness setting is maxed out - sounds like a software issue to me,” he notes.
Customers have also been complaining about actual brightness issues with their iMacs in that it wasn’t even from left to right. However, the issue mostly affects older, 24-inch systems, according to a piece by Silvermac.
Interestingly, Apple fails to provide additional details about its brightness update. The company only says it addresses an issue with display brightness on 21.5-inch iMacs shipped in Mid 2010.
The software update requires Mac OS X 10.6.4, the latest version of Snow Leopard available.
Weighing in at 378 KB, the installer package is available for free download via Apple’s automatic Software Update mechanism, or via the Support / Downloads area of its web site (manual download). iMac owners can grab the update right now via the link below.
Download iMac (Mid 2010) Display Brightness Update (Free)
Those who apply the update are encouraged to report any changes they've noticed in the behavior of their iMacs' screens. It goes the same for those who don't see anything changed at all.