Apple has extended the warranty on several batches of video cards installed in Mac Pro desktop computers sold from early 2008 onwards.
The ATi Radeon HD 2600 XT video cards, which can show distorted video or no signal at all in some cases were installed in Mac Pro (Early 2008) models sold worldwide and as after-market add-ons through various Apple-approved outlets.
Apple says, "If your Mac Pro experiences distorted video or no video issues and has an ATI Radeon HD 2600 XT card in it, you will need to bring your computer's serial number and the graphics card into an Apple Authorised Service Provider or an Apple Retail Store location for verification and to exchange the affected graphics card for a replacement."
The company says that, if your video card isn't misbehaving in any way you won't be getting a new card and you'll just have to take your chances with the extended warranty which covers the faulty parts until three years after the date of purchase or July 31st 2011, whichever comes later.
Apple also says that it will continue to keep an eye on returns and extend the warranty further in necessary.
The broken cards have serial numbers which contain the following last four digits (* denotes any character): YPU(*), YPV(*), 1M4(*), 1M5(*), 29H(*), or 29G(*)