I've been using Linux mint for nearly 10 years but I am now stumped.
My screen blanks after 2 or 3 minutes even though the power is set to never and the screensaver is only set to activate after 2 hours. It's driving me mad. It even activates whilst I am watching a video.
I'm on Mint 'Mate' 19.2

Hi,

the post title says "screen locking" but the text talks about the screen blanking. Can you confirm what you are actually seeing? I wonder if display itself is entering some power saving mode or if it is your GUI blanking/locking.

Evo2.

The screen goes black as if expecting to start the screensaver. I have to touch my mouse or keyboard for it to reactivate. But, as I said previosly, I have been through all the settings and they are all turned to off. I've looked online to find the answer and I've been direct to gconf or gsettings none of which are applicable to mint 19.2. I just want to stop it turning the screen off.
Thank you in advance.

Please make sure you looked in
a) the screensaver settings
b) the power management settings - ALL tabs!
and tell us exactly what you find there.

And stop using that angry smiley for every post.

It makes me mad.

Power settings (On AC power).
Actions: Put computer to sleep when inactive for - set to never
Display: Put display to sleep when inactive for - set to never

Screensaver.
Regard computer as idle after - set to maximum 2 hours
Activate screensaver when computer is active - unticked
Lock screen when screensaver is active - unticked

Irrespective of these settings my screen turns off after 3 minutes.

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So your power manager has only 1 Tab?
And why do you write (On AC power)? Is it different on battery?

Please answer this also.

After that, also show us the output of

xset -q
Keyboard Control:
auto repeat: on key click percent: 0 LED mask: 00000000
XKB indicators:
00: Caps Lock: off 01: Num Lock: off 02: Scroll Lock: off
03: Compose: off 04: Kana: off 05: Sleep: off
06: Suspend: off 07: Mute: off 08: Misc: off
09: Mail: off 10: Charging: off 11: Shift Lock: off
12: Group 2: off 13: Mouse Keys: off
auto repeat delay: 500 repeat rate: 30
auto repeating keys: 00ffffffdffffbbf
fadfffefffedffff
9fffffffffffffff
fff7ffffffffffff
bell percent: 50 bell pitch: 400 bell duration: 100
Pointer Control:
acceleration: 2/1 threshold: 4
Screen Saver:
prefer blanking: yes allow exposures: yes
timeout: 0 cycle: 0
Colors:
default colormap: 0x20 BlackPixel: 0x0 WhitePixel: 0xffffff
Font Path:
/usr/share/fonts/X11/misc,/usr/share/fonts/X11/Type1,built-ins
DPMS (Energy Star):
Standby: 600 Suspend: 600 Off: 600
DPMS is Enabled
Monitor is On

Yes, the only power setting there is, is as previously described and there is nothing anywhere relating to laptop settings, not that I can find.
It is a desktop PC.

What about this?

That will let us know if there's a rogue screen blanker running

which mint desktop are you using? I experienced the same issue with Mint XFCE...

Try setting that to a number or disable energy star feature, until you get it figured out.

Which video player are you using? Yes, this matters, because some video players (like MPlayer and mpv) actually have code to try to suspend the screen saver/locker/blanker.

Anyway, you can always install Caffeine or Caffeine Plus and let it solve the problem.

I found this so somewhere there is a python script that is running to activate the screensaver.
Any ideas?

#!/usr/bin/python3

""" Launch the cinnamon screensaver lock dialog
"""

import os

os.system("/usr/share/cinnamon/cinnamon-screensaver-lock-dialog/cinnamon-screensaver-lock-dialog.py")

How did you find that? Does top/htop/ps -e show you that a python script is running?

/usr/share/cinnamon/cinnamon-screensaver-lock-dialog/cinnamon-screensaver-lock-dialog.py

That is the path of that python script. If you think that is running, and you don't want it, kill it. Look and see what launched it.
man kill
man pkill

https://github.com/linuxmint/cinnamon-screensaver
https://forums.linuxmint.com/viewtopic.php?t=161482
https://forums.linuxmint.com/viewtopic.php?t=283954

Sure it isn't in some auto launch?

"somewhere?" It appears to be here:

Teckk, you're a star.
xset worked perfectly.
Thank you.

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