Apple has launched a graphics card replacement program for select mid-2011 iMacs according to a notice issued to Apple Support employees. The iMac in question is the model released in May 2011 with Sandy Bridge processors and Thunderbolt ports.
Apple has determined that some AMD Radeon HD 6970M video cards used in 27-inch iMac computers with 3.1GHz quad-core Intel Core i5 or 3.4GHz quad-core Intel Core i7 processors may fail, causing the computer’s display to appear distorted, white or blue with vertical lines, or to turn black. iMac computers with affected video cards were sold between May 2011 and October 2012.
The last four characters of the serial number must contain one of the following groups (for example, xxxxxxxxDHJQ):
- DHJQ, DHJW, DL8Q, DNGH, DNJ9, or DMW8
- DPM1, DPM2, DPNV, DNY0, DRVP, DY6F, F610