The Apple has released a replacement program for the graphics card in the mid~2011 27~inch iMac configurations. According to the note sent to the Apple support employees,
[sws_blockquote_endquote align=”” cite=”” quotestyle=”style02″] Apple has strong-minded that the AMD Radeon HD 6970 video cards are being used in the 27~inch iMac computers with the 3.1GHz quad~core Intel Core i5 or the 3.4GHz quad~core Intel Core i7 processors might fail, affecting the PC’s display to appear slanted, blue or white with the vertical lines, or to turn black. The iMac PCs with the affected video cards were vended between May 2011 & October. [/sws_blockquote_endquote]
The exaggerated iMacs comprise serial numbers with last 4 characters of DHJW, DL8Q, DHJQ, DNGH, DMW8, DNJ9, DPM2, DPM1, DNY0, DPNV, DRVP, F610, or DY6F. The mistakes have been noted previously in the both Apple Support forums and MacRumors forums.
The Apple will swap the graphics card of the affected iMacs with the above-mentioned serial numbers at no cost for up to 3 years from the date that the PC was purchased, that makes initial adopters eligible until the May 2014.
Replacements can be started via AppleCare, Genius Bar, or the Apple Authorized resellers and iMac consumers that paid to have a graphics card swapped are eligible for a refund.