Screen off/blanking

[Daniel Dalton <d.dalton@iinet.net.au>]

Hi, 

For both powersaving and privacy bennefits I'm trying to turn my
laptop's screen off. This was easy as 
vbetool dpms off 
on my old machine, but now I get an error with vbetool on the new
machine (Lenovo thinkpad X230):
7204a038:5154166: 00 ILLEGAL X86 OPCODE!
halt_sys: file , line 91711232
Function not supported

I looked at the debian wiki and use the script provided to turn off the
screen in the GUI and the setterm command to do it for the console. 
However I still have some problems. 

1. How to turn back on the screen (for both methods)? This might be
required on the fly when someone needs to see what I'm doing. 
2. I notice when I switch from console to gui the screen can come back
on. Is there a solution to this? Is there a place I can put a call to
the script to have it called every time I switch virtual consoles
including to number 7 the gui. 
3. I no setterm appears to be useless under a screen session. Does this
mean I'll just have to open another virtual console or drop out from the
screen session to toggle the screen on and off if I need too? 

Thanks, 
Daniel