Apple Cinema HD Display 30'' black screen, power light blinking

Sometime the cross-talk of signals is caused by the wiring behind the computer, touching. Separate the wiring.

Blinking light on Apple cinema display usually indicates insufficient power from the power supply. Test it with another power supply from ANY cinema display (23" and 27" power supplies are ok to test with).

Check your connection to the screen. You may have a running application / process that requires a lot of processing power from your Graphics Processing Unit (GPU). If you wait until the application has completed its task, or quit the program, videos should run fine.

the best sway to deal with apple products is to bring it to apple themselves......9 out of 10 times they will fix it for nothing

The only way to test is to use a known working power supply or known working cinema display with the parts you already have.

have it service with registered technicians

http://support.apple.com/kb/HT1379

Try this first this puts everything back to how it is supposed to be, possible "corruption"

I have an older 20" display. I have had this same problem on occasion, and coincidentally, just experienced it again this morning. It seems to occur after I do an OS update. I powered down the computer, disconnected the display, reconnected by pushing firmly into place, then powered up. The flashing stopped and the display works fine. You might have a different problem, but that simple solution worked for me.

you need to open it up and replace the backlight(s), you will be quoted nearly the price new to get this fixed. might aswell bin it or eBay it! you intrestedin selling it?

Hi all,
I had the “short long short” blinking led problem with my
23′ ACD after a power outage which left my screen blank and
my cheek wet with a tear for my baby. I read somewhere that
a guy was getting a 1 volt reading on the middle pin of his
damaged 90 watt power block. I figured maybe the display might
work if I could somehow block the middle pin. So I cut a small
strip of paper wide enough to block just the middle pin and long
enough to cover both sides and it looked like a “W”. I gingerly
pressed it into the brick receptacle with a toothpick leaving
just a little slack so it would not tear when I pushed in the
small white plug. It was a bit of a tight fit but guess what.
IT WORKED… I am now enjoying my beloved monitor anew and saved
$$$ on replacement brick or repair.
If you want to try it and you feel you’ve nothing to lose, make
sure you cover just middle pin (both sides) and you may have to try a couple of times. It worked for me, I hope you have good luck too.
Regards, Moozler