Turn screen on and off on Windows

Question

Directly into the problem, I was trying to implement the screen/display/monitor Off and On feature into my primary program. I researched a bit and found this one answer interesting. So, tried testing it. Here's the code in a nutshell:

import time
import win32gui
import win32con

def ScreenOFF():
    """
    Function to turn off the screen.
    """
    return win32gui.SendMessage(win32con.HWND_BROADCAST,
                            win32con.WM_SYSCOMMAND, win32con.SC_MONITORPOWER, 2)

def ScreenON():
    """
    Function to turn on the screen.
    """
    return win32gui.SendMessage(win32con.HWND_BROADCAST,
                            win32con.WM_SYSCOMMAND, win32con.SC_MONITORPOWER, -1)

ScreenOFF()
time.sleep(5)
ScreenON()
time.sleep(5)

The Screen Off was working great but while executing the Screen On function, The Screen only turns on for a second and then again it turns off immediately. I could not even reason now why that happens !

Also tried this more primitive approach but here too is the same problem:

import time
import ctypes

def ScreenOFF():
    """
    Function to turn off the screen.
    """
    ctypes.windll.user32.SendMessageW(65535, 274, 61808, 2)

def ScreenON():
    """
    Function to turn on the screen.
    """
    ctypes.windll.user32.SendMessageW(65535, 274, 61808, -1)

ScreenOFF()
time.sleep(5)
ScreenON()

Here's another reference link that might help here.

There are github repos on screen off, like this one, but NONE on Screen On !

Please suggest me if there are any fixes to this or other better ways to turn the screen On/OFF ?

You can pass 1 as parameter. It is for low power, but it will work. Most answers around suggest to fake a mouse movement. — azelcer, Feb 03 '22 at 04:35
Passing 1 does not seem to work on my laptop, and I also tried faking mouse movement using `pyautogui.move(1,1)`, but that does work either... — PNxZEN, Feb 03 '22 at 05:29
If possible, please upvote this question to reach as many users as possible... — PNxZEN, Feb 03 '22 at 05:41

score 0 · Accepted Answer · answered Aug 09 '22 at 14:18

0

Not a actual solution to the issue where it just turns as soon as it turns on, but I found a way to keep it not going off.

Not a very great way but it works

import time
import ctypes
import win32api, win32con
def screen_off():
    ctypes.windll.user32.SendMessageW(65535, 274, 61808, 2)
def screen_on():
    ctypes.windll.user32.SendMessageW(65535, 274, 61808, -1)
    move_cursor()
def move_cursor():
    x, y = (0,0)
    win32api.mouse_event(win32con.MOUSEEVENTF_MOVE, x, y)

screen_off()
time.sleep(3)
screen_on()

If you move the cursor or type something the screen will stay on, so

answered Aug 09 '22 at 14:18

eroc123

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for me on my laptop the code works perfectly as intended. The use of `win32api.mouse_event(win32con.MOUSEEVENTF_MOVE, x, y)` instead of `pyautogui.move(1,1)` seems to do the trick. – eroc123 Aug 28 '22 at 05:36
Thanks... `win32api` does the Trick :> – PNxZEN Sep 17 '22 at 07:03
Is it possible to only turn off one specific monitor? For instance: I have 3Monitors, would I be able to write a Python script to only turn off the lateral two? – Kelbig Oct 18 '22 at 20:03

score 0 · Answer 2 · answered Aug 29 '23 at 14:48

There is a python package called monitorcontrol that you can use to control monitor power mode, contrast, input source and brightness (luminance). Here is example to power on and off monitor:

from monitorcontrol import get_monitors
from time import sleep

for monitor in get_monitors():
     with monitor:
         monitor.set_power_mode(4) # soft off
         sleep(3)
         monitor.set_power_mode(1) # on

If you want to use ctypes instead of this package see this answer to turn on and off the monitor with ctypes and windows monitor api

Turn screen on and off on Windows

2 Answers2