If you purchased an iMac between May 2011 and October 2012, and you are experiencing issue with your unit’s display, then you may want to verify that you are eligible for a free video board replacement.
Apple has issued a notice that details how, over the past two years, a number of users have received iMacs with troublesome AMD Radeon HD 6970M cards inside select 27-inch models. Apple states that the issue causes “the computer’s display to appear distorted, white or blue with vertical lines, or to turn black”.
As 9to5Mac reports, only models that contain the following groups of characters at the end of their Serial Number are eligible for a replacement card:
~ DHJQ, DHJW, DL8Q, DNGH, DNJ9, DMW8, DPM1, DPM2, DPNV, DNY0, DRVP, DY6F, F610.
Below is an example of the problems exhibited by a faulty HD 6970M:
Users that have purchased an iMac which is experiencing display issues and lists a serial number configuration as listed above are able to receive a replacement board– so long as they take advantage of this offer within three years of their iMac’s purchase date.