Chosen Solution
I currently have the late 2011 Apple Thunderbolt Display 27 inch. The screen is black but is detected on my MacBook Pro. I took it to a Apple technicians and reviewed diagnostics. They told me that the lcd display is not good anymore. And it was gonna be around 800 dollars to replace it since it was Out of warranty. I read on ifixit that the Thunderbolt Display has the same display as the 2009 27” iMac. So I was wondering if can replace my Thunderbolt Display using the 2009 iMac display.
Before you spend the money on a display make sure its not a backlight issue. Take a flashlight held against the display at a sharp angle are you able to see the faint image of your desktop icons? If you do, the issue is the backlight circuit within the displays logic board. This has been a common issue in many of these. Checkout the IFIXIT Teardown here: Apple Thunderbolt Display Teardown jump down to Step12 - Supertex HV9982 3-channel switch-mode LED driver IC
