http://www.macnn.com/articles/11/12/12/fixes.rare.issue.with.fan.noise/
Apple issues firmware update for Thunderbolt Displays
updated 06:00 pm EST, Mon December 12, 2011
Fixes rare issue with fan noise
Late this afternoon, Apple issued a fix for a fan noise issue that affected a small number of Apple Thunderbolt Displays in a firmware update labeled version 1.1. The 942KB file launches automatically once installed in the Utilities folder and shows on-screen instructions on going through the firmware update procedure. This is the first update specifically for Thunderbolt Display devices, though an earlier patch was issued for Thunderbolt-capable Macs generally in June.
In addition to the fan noise fix, the update "improves stability" according to Apple. It requires OS X 10.6.8 for Snow Leopard users or 10.7.2 or later for Lion users. The update will appear in Software Update or is available directly from Apple's support website.
