How to prevent MacBook Pro from sleeping with turned off external display? I have two displays connected to my MacBook Pro Retina 2015, running 10.10. It is connected to power, so it will not sleep once I close the lid. 

However, if I am doing long during calculations over night I want to power off the external displays. This is not possible, since as soon as I shut down the last display the system stops to calculations, compression tasks etc.

Is there a way to keep OS X awake on a power book with a closed lid and turned off displays while connected to power?
Move all windows from your external displays to the mbp's display
Remove your display connector/s
Voila, It works!


If it doesnt work, Try Resetting the SMC and PRAM/NVRAM. Google about how to do that..