Q: My external display turns off after I close the lid on MBP

I am using a Mini DisplayPort to HDMI to connect to an ASUS VS278Q-P display. I have followed the instructions on http://apple.co/1TvTMQB to the letter. I am using a magic trackpad with USB keyboard so I've tried both sets of instructions.

Specs

MBP 17" late 2011

2.4 GHz Intel Core  i7

16 GB 1333 MHz DDR3

AMD Radeon HD 6770M 1024 MB

Enable closed-display mode

Use these steps to enable closed-display mode.

If the external display isn't recognized when it's connected and your Mac is powered on, try connecting the display while your computer is asleep or off. Then wake or turn on the computer after you connect the display.

If you're using a USB keyboard and mouse

1. Make sure your Mac notebook is plugged in to an outlet using the AC power adapter.
2. Connect a USB keyboard and mouse to your Mac.
3. With your Mac turned on and the display open, connect the Mac to the appropriate port on the external display or projector and turn the display or projector on. Use an appropriate Apple video adapter if necessary.
4. After your Mac notebook's Desktop appears on the external display, close the computer's lid.
5. When you close the lid:
   • In OS X Lion v10.7 and later, the external display changes to a blue screen, then shows your Desktop.

If you're using a wireless keyboard and mouse

1. Make sure your Mac notebook is plugged in to an outlet using the AC power adapter.
2. Verify that Bluetooth is turned on in the Bluetooth pane of System Preferences or the Bluetooth menu icon .
3. Pair your Bluetooth keyboard or mouse with your Mac.
4. In the Bluetooth pane of System Preferences, click Advanced and make sure the checkbox next to Allow Bluetooth devices to wake this computer is selected.
5. With your Mac turned on and the display open, connect the Mac to the appropriate port on the external display or projector and turn the display or projector on. Use an appropriate Apple video adapter if necessary.
6. After your Mac notebook's Desktop appears on the external display, close the computer's lid.
7. When you close the lid:
   • In OS X Lion v10.7 and later, the external display changes to a blue screen, then shows your desktop.