Thank you for all the suggestions throughout this and other threads. I’m still having an issue with my 24” LED Cinema Display. I can get it to work with the brightness all the way down, but once I try to raise the brightness, it begins to blink and eventually goes black. I have a short video of this behavior here: https://youtu.be/4UoOGBID95I
I tried taking the display apart and reseating all the connections. Does anyone else have any other things I should try?