If your display detects the wrong adapter connected to it, it will flash its power light in a repeating short-long-short error code. Check the table and picture below to learn which power adapter to use with the display.
As you can see in the picture above, each power adapter has the power rating, in watts, printed on it. Make sure your display is using a compatible adapter:
|I have this display...||...which adapters can I use?|
|65 W||90 W||150 W|
|Apple Cinema Display (20-inch DVI)||yes||yes||yes|
|Apple Cinema HD Display (23-inch DVI)||no||yes||yes|
|Apple Cinema HD Display (30-inch DVI)||no||no||yes|