Chosen Solution
Hello, We own a 27" intel iMac (A1312 model) and since a few months now, the left part of the screen is turning to dark frequently. This happens several times a day, without any evident cause related to its activity. Its serial number ends with DHJP . I just wonder if this might be related to a faulty LED Backlight Board or display cable ? A picture of the screen can be seen here : http://www.bru.licr.org/~lejeune/images/… I would appreciate any thought on the subject. Jo Lejeune Update (01/27/2016) Thanks Dan and aebelcarris for your reply. Now I’ve just to decide to replace either the backlight cable or the board, or both … I’ll keep you informed. Regards, Jo Update (03/20/2016) Replacing the LCD panel did the job. Nor the backlight cable nor the board were involved in the troubles we had. Of course replacing the LCD panel has a high price tag… Jo
I would say the backlight cable maybe damaged here.
What are the last four figures of your serial number (located on the bottom of your stand? iMac (27-inch): AMD Radeon 6970M Video Card Replacement Program 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.
most likely it is a backlight issue. whoops i just saw that dan already answered it. well I concur with dan
