I've been using this Macbook Pro for about 2 years now and recently got an external display for it. It is connected via a Thunderbolt to HDMI adapter.
Before I got the display, I could simply shut the lid to enable clamshell mode and the system would mostly power down (HDD would stop etc).
However, now whenever I shut the lid, the external monitor becomes the primary display and continues to work and keep the laptop awake. I do not have an external mouse, trackpad or keyboard connected.
Is there any way to make the laptop go back into clamshell when the lid is shut and turn both displays off? I would prefer if it were possible without disconnecting the external display, as every time I do that I lose my window arrangement across displays.
I found this, but I don't want point two. I want both displays to wake up when I open the lid, and both displays and the mac to sleep when I close it.