Apple LCD displays: Power light flashes

Some Apple LCD displays will alert you if they detect an error condition.

This article has been archived and is no longer updated by Apple.

If one of the Apple LCD displays detects an error condition, the power LED will flash in a certain pattern to indicate the issue.

short, short, short The display is detecting wrong video format or an unsupported resolution.
Verify that your equipment is compatible and restart the computer. If the issue continues, reset the PRAM.
short, long, short Make sure you are using the correct power adapter with the display. This alert will only appear on displays built in 2004 or later which require an external power adapter.
short, short, long The display is detecting a backlight error. Check your display's power connections and restart the computer. If the problem continues, contact Apple or an Apple Authorized Service Provider.
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