Disable blanking the text terminals.

Jessie
Open:

$ sudo nano /boot/cmdline.txt

Addd:

consoleblank=0

Wheezy
Open:

$ sudo nano /etc/kbd/config

Change to:

BLANK_TIME=0
BLANK_DPMS=off
POWERDOWN_TIME=0

Or add in:

$ sudo nano /etc/rc.local 
setterm -blank 0

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Blanks the console after 10 seconds.

Jessie
Open:

$ sudo nano /boot/cmdline.txt

Addd:

consoleblank=10

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