If you’re discovering that your Mac wakes up from sleep randomly without any interaction, it’s not a ghost, but rather some settings that probably need changed around. Here’s how to fix it.
When you put your Mac to sleep, it essentially powers down, but remains on standby. So while most of the components are shut off, like the processor, storage drives, etc., the memory is still on so that when you wake it up from sleep mode, it will instantly be back to where you left off.
Sleep mode is great for when you don’t want to completely shut down your Mac, but want to conserve power when you’re not using it.
However, sleep mode is rather pointless if your Mac randomly wakes up from sleep mode at times. Sometimes, it may wake up randomly one evening, or the problem could be more severe where it wakes up immediately after every time you try to put it to sleep.
Your Mac waking from sleep mode randomly can be pretty frustrating to say the least, but it’s a problem that has some easy fixes. Plus, it’s a problem that can be a little scary, making you think that there’s a ghost or some paranormal activity going on in your house.
In any case, here’s how to fix your Mac randomly waking up from sleep mode.
A big culprit of most sleep mode problems on Mac comes from the USB devices that you have plugged in, like a mouse, keyboard. etc., so it might be a good idea to see if any of your USB devices are causing the problem.
To find out if a mouse or keyboard is causing the problem, temporarily set your Mac’s automatic sleep mode to its shortest setting in System Preferences > Energy Saver. From there, slide the slider next to Computer sleep all the way to the right.
Next, unplug all of your USB devices and wait for your Mac to automatically go to sleep. If it doesn’t wake up from sleep like it usually does with your problem, then it’s one of your USB devices that’s causing the issue. Redo all of this but only plug one USB device back in until you figure out which device is causing the issue.
So why would a USB device be the culprit? It could be that a key on your keyboard is malfunctioning and sending that info to your Mac so that it can never truly go to sleep. The same could happen to the mouse, where one of the buttons could be stuck and is pressed down the whole time, preventing your Mac from sleeping.
If your Mac is connected to the internet, it’s possible that it’s randomly waking from sleep because there’s internet activity or other network activity occurring that wakes it up.
This is especially the case if you have your Mac connected to a network drive or server in your house. Whenever, the network drive is active, it could send a command to your Mac to wake up. This can also be the case for iTunes sharing, Printer sharing, and File sharing.
To prevent this from happening, go to System Preferences > Energy Saver and uncheck the box next to Wake for network access. This will prevent any outside internet or network activity from waking up your Mac randomly.
Reset the SMC
The above two solutions are what cause random wake ups 99% of the time, so if all else fails, it wouldn’t be a bad idea to reset the SMC.
Sleep mode on your Mac is controlled by your Mac’s power manager, which is called the System Management Controller, or SMC. It stores options for when the system sleeps, among other features throughout your computer. It’s possible that information on the SMC could get corrupted and cause random wake ups.
To fix this, start by put your Mac to sleep and wake it up after it has gone to sleep. Then, restart your Mac. Wait for it to fully boot up and then completely shut it down.
On a MacBook, plug in the charger so that it’s getting power and then press the Shift, Control, Option keys on the left side of the keyboard, as well as the Power button all at once. Hold for a second or two and then release all the keys and buttons at the same time. Then, turn on your Mac.
On a Mac that’s powered with a power cord, all you have to do is shut down the machine, unplug the power cord, wait fifteen seconds, plug the cord back in, wait five seconds, then turn on your Mac.