You have no idea but that's a tricky one to do, there are a ton of ways to do it but almost none of them work. Here's what works.
Go to Menu/Control Menu/Settings/Default Applications for LXSession->Autostart and enter these commands in the "+Add" line, one by one, and pressing <enter> after each one: xset s off xset s noblank xset -dpms
It will then display like this:
Reboot or at least logout and you'll no longer have the screen blanking after 600 seconds (10 minutes) set by default in the kernel (I think).
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So what did you do? You set some parameters for xset at the start of your session, regarding screensaver, screen blanking and Energy Star settings, in this order.
To check your current xset configuration, open the terminal and type this: xset q
You'll then be shown what's set. You can see there these which are the ones you want to change:
$ xset q
...
Screen Saver:
prefer blanking: yes allow exposures: yes
timeout: 600 cycle: 600
...
DPMS (Energy Star):
Standby: 0 Suspend: 0 Off: 0
DPMS is Enabled
Monitor is On
After you fallowed the instructions above, if again you type xset -q in the terminal, you'll see that now it has changed to: $ xset q ...
Screen Saver:
prefer blanking: no allow exposures: yes
timeout: 0 cycle: 600
... DPMS (Energy Star):
Standby: 600 Suspend: 600 Off: 600
DPMS is Disabled
So now you can see that there's no blanking, no timeout and DPMS is disabled.
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In the future if you want to turn them on again, just go to Menu/Control Menu/Settings/Default Applications for LXSession->Autostart and remove all the xset commands you entered.
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If during a session you wanna turn on some of the settings that you disabled, just enter in the terminal the proper commands following.
- enable blanking screensaver: xset s blank - ten minute interval:
xset s 600 600
- enable power management: xset +dpms
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For more information you can type xset on the terminal and press <enter>, you'll be shown all the available options.