OS X Mavericks: If the power light on your flat-panel display is flashing
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If your flat-panel display isn’t working correctly, its power button may flash to alert you to an error condition.
- If you see three short flashes, the display is receiving the wrong video format or is set to an unsupported resolution. Make sure your display is compatible with the Mac you’ve connected it to, then restart the Mac. If the problem continues, try resetting the parameter random-access memory (PRAM) by shutting down the Mac, then turning on the Mac while pressing and holding the Option–Command (⌘)-P-R keys. Hold the keys down until the Mac restarts and you hear the startup sound for the second time.
- If you see a “short, long, short” flash pattern, make sure you’re using the correct power adapter for the display.
- If you see a “short, short, long” flash pattern, the display is detecting a backlight error. Check your display’s power connection and restart your computer. If the problem continues, contact Apple or an Apple Authorized Service Provider.
Published Date: Oct 20, 2015