On Sunday 01 July 2018 06:16:01 pm dep wrote:
> optimize its configuration, i'm trying to set the screen not to just blank
> but to power down when the screensaver is called.

I have not read any of the other replies, but an alternative is to add an 
Applet to your Panel that calls this Batch file.  (I use the Gnome-Mines 
system icon for grins and place it on the far opposite side from the TDE 
Menu.)

===========
goodnight.sh
#!/bin/bash

dcop kdesktop KScreensaverIface lock
sleep 3
xset dpms force standby
===========

It locks the session and after 3 seconds turns the screen off.

I've used this for 5+ years on my old Dell laptop (with CentOS, Ubuntu, Gnome, 
KDE, TDE), so I don't remember if it's hardware specific, so change as needed 
for your hardware.

Best,
Michael