How to Fix Mac Not Going Into Sleep Mode

How to Fix Mac Not Going Into Sleep Mode

You probably know that your Mac has a mode called Sleep mode, a low power mode meant to save electrical consumption when your Mac is inactive. If you left your Mac turned on and went somewhere for a while, it would automatically go into Sleep mode after some time. Although it is an automatic process, you can also put your Mac to Sleep mode on purpose. It can be more convenient than shutting it down completely as you don't need to wait for the Mac to boot when you are ready to use it.

How to Fix Mac Not Going Into Sleep Mode

Nowadays, many devices, like phones and computers, have a sleep mode, but Apple developed more than one sleep mode, and they all work in a slightly different way. As briefly mentioned above, one of the sleep modes is the standard Sleep mode, which leaves RAM (Random Access Memory) powered on, and it lets the user wake up the Mac and start using it without having to wait for the Mac to boot. There is a possibility to set a preferred timespan before Mac goes into sleep mode or completely stop it from sleeping. Sleep mode is set by default and is called "hibernate mode 0".

Another power-saving mode is called the Hibernation mode, which turns off the RAM when your Mac is sleeping. Before the Mac goes into sleep mode, the startup drive copies RAM information. When you wake up your Mac from Hibernation mode, the startup disk downloads necessary information to the random access memory. This is why wake-up time is a bit longer than when waking up from only sleep mode. This mode was set by default for Macs released before 2005 and is called "hibernate mode 1".

Safe Sleep mode is a mode that will let you recover your data in case of hardware damage, battery, or other part failures, as it copies data from RAM before your Mac goes into sleep mode. However, it is different from Hibernation mode because while the Mac is in sleep mode, the RAM remains powered. That is why the wake-up process is as quick as waking up your Mac from simple Sleep mode. Safe Sleep mode is called "hibernate mode 3" and is set by default for portable Macs released after 2005. Unfortunately, not all laptop Macs support this mode.

And the fourth energy-saving mode is called Mac Standby mode. The purpose of this mode is to save the battery charge. Your Mac goes into Standby mode after some time of being in Sleep mode. For Macs released before 2013, it takes an hour for it to get into Standby mode. Macs released after 2013 go into Standby mode after about three hours of being into Sleep mode. When your Mac goes into the Standby mode, the session gets recorded to an SSD (Solid State Drive). Mac's battery can last 30 days in Standby mode without being plugged into a power source.

Regardless of your Mac is a desktop or a laptop, Sleep mode puts it into a low power mode. It slows down the hard disk's spin speed, deactivated video output, and might turn off the display. Laptops, however, need to save as much energy as possible. Hence sleep mode also turns off random access memory but only when in the hibernation and safe sleep modes. It also deactivated expansion card slots, built-in modem (if present), AirPort functions, audio input and output, keyboard illumination (if present), and Bluetooth. The USB port's operations are limited, and the optical drive spins down (if present).

Sleep mode and other power-saving modes are an excellent solution for saving battery life and preventing your Mac from heating up when it is not in use for some time. Unfortunately, your Mac might experience some issues that can prevent it from going into Sleep mode or stay in sleep mode, or it just might be an issue with an improperly set setting. The troubleshooting steps below will help you to determine the problem and solve it.

Table of Contents:

Check Energy Saver Settings

Sometimes the solutions to all your problems are as simple as checking the right settings. Before doing anything else, check if the Energy Saver settings are set correctly to your preference.

If you are using a Mac desktop:

1. In the upper menu bar, click on the Apple logo.
2. Go to "System Preferences".
3. In the "System Preferences" window, find and click on "Energy Saver".

Go to Energy Saver

4. Drag the "Computer sleep" and "Display sleep" sliders to set the amount of time that should pass before your computer goes to sleep. These options should not be set to "Never".

Set Computer sleep and Display sleep time

If you are using a Mac notebook:

1. In the upper menu bar, click on the Apple logo.
2. Go to "System Preferences".
3. In the "System Preferences" window, Find and click on "Energy Saver" or "Battery".
4. Go to the "Battery" tab and drag the "Turn display off after" slider to set the amount of time that should pass before your Mac goes to sleep mode. This option should not be set to "Never".
5. Go to the "Power Adapter" tab and deselect "Prevent computer from sleeping automatically when the display is off" and "Wake for network access".

There is also a possibility that a wake-up and sleep schedule is set. Check the setting to see if this might be the issue for your problem.

1. In the upper menu bar, click on the Apple logo.
2. Go to "System Preferences".
3. In the "System Preferences" window, Find and click on "Energy Saver" or "Battery".
4. At the bottom of the window, click on the "Schedule" button.

Click on Schedule

5. If you have previously set a schedule for wake up and sleep mode, edit it if your preference has changed. Or you can just uncheck the boxes to turn off the set schedule.

Turn off set time in Schedule

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Check For Apps That Prevent Mac to Sleep

Check if there are any apps that might prevent your Mac from going into Sleep mode.

1. Open the Activity Monitor from Launchpad, Finder, or Spotlight.
2. When the Activity Monitor window pops up in the upper menu, click on "View".
3. Then click on "Columns", and at the bottom, click on "Preventing Sleep".

Enable Prevent Sleep tab in Activity Monitor

4. A "Preventing Sleep" column will appear in the Activity Monitor window. If you see the word "Yes" next to an app, it means that the app is preventing your Mac from going to sleep.
5. Click on the app that is causing problems.
6. At the top left corner of the window, click on the "X" icon.
7. Then click on "Force Quit".

Force Quit app that is preventing Mac from sleep in Activity Monitor

If it says "No" next to an app, that means the process does not cause any issues.

If you already know what app is causing trouble, you can kill the process faster:

1. Simultaneously pressing the Command + Option + Esc keys on your keyboard.
2. Find and click on the application that is causing trouble.
3. Click on "Force Quit".

Press Option + Command + Esc and Force Quit app

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Check if Bluetooth is Preventing Mac to Sleep

Check Bluetooth settings if devices connected with Bluetooth are continually waking up your Mac.

1. In the upper menu bar, click on the Apple logo.
2. Go to "System Preferences".
3. In the "System Preferences" window, Find and click on "Bluetooth".

Go to Bluetooth

You can also open Bluetooth settings by clicking on the Bluetooth icon in the upper right corner of your screen and then on "Open Bluetooth Preferences".

Open Bluetooth Preferences

4. Click on the "Advanced" button.
5. Uncheck the box next to "Allow Bluetooth devices to wake this computer".
6. Then click on "OK".

Uncheck Allow Bluetoot to wake this computer

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Check Printer Settings

If you recently tried to print something and it got stuck, or an error occurred, you might have print jobs waiting in the printing queue, and that can prevent your Mac from sleeping.

Check and Clear The Printing Queue:

1. In the upper menu bar, click on the Apple logo.
2. Go to "System Preferences".
3. In the "System Preferences" window, Find and click on "Printers and Scanners".

Go to Printers & Scanners

4. Select the printer you were using.
5. Click on the "Open Print Queue" button.

Clear print queue

6. Delete all print jobs that got stuck.

Turning off the Printer Sharing:

1. In the upper menu bar, click on the Apple logo.
2. Go to "System Preferences".
3. In the "System Preferences" window, Find and click on "Sharing".

Go to Sharing

4. Uncheck the box next to "Printer Sharing".

Disable Print Sharing

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Find The Issue Using Terminal

By using Terminal commands, you can see who is preventing your Mac from going to Slee mode.

1. Open Terminal from Launchpad, Utilities, Finder, or Spotlight.
2. In the Terminal window, enter the command line: pmset -g assertions
3. When you see the results look for "PreventUserIdleDisplaySleep", "PreventSystemSleep" and "PreventUserIdleSystemSleep".
4. Check if you see number 1 displayed next to any of the listed in step 3.
5. Under "Listed by owning process", check which setting or application is preventing your Mac from sleeping.

Check issue using Terminal

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Disconnect Peripherals

If you have any USB, Thunderbolt storage, and other devices connected to your Mac, check if any of them are malfunctioning as it can cause Sleep mode issues. Unplug all cables and plug them back in one by one to see which of them prevent your Mac from going into Sleep mode.

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Reset NVRAM

If you still can't find what might be preventing your Mac from going into Sleep mode, reset the non-volatile random-access memory.

1. Turn off your Mac.
2. Turn on your Mac and, at the same time, simultaneously hold down Option + Command + P + R keys on your keyboard. You can let go of the keys after 20 seconds.
3. Wait for your Mac to reboot.

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We hope that this article helped you solve the Sleep mode problem that your Mac experienced. Let us know in the comments which method helped!

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About the author:

Tomas Meskauskas

I am passionate about computer security and technology. I have an experience of 10 years working in various companies related to computer technical issue solving and Internet security. I have been working as an editor for pcrisk.com since 2010. Follow me on Twitter to stay informed about the latest tech news or online security threats. Contact Tomas Meskauskas.

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