If your MacBook won’t stay asleep — the fans kick back on inside a closed bag, the screen lights up in the middle of the night, or it never sleeps at all — the cause is almost always a wake trigger or a power assertion, not a failing logic board. Here is how to find and kill it, in the order that fixes the most Macs first.
First, confirm it is actually a wake problem
A Mac that runs hot in a bag is usually waking, not refusing to sleep. Open Terminal (Applications › Utilities) and run:
pmset -g log | grep -e "Wake " -e "DarkWake" | tail -20
Each line shows what woke it — Network, Bluetooth, EthernetWake, UserActivity, or a maintenance wake. That word is your suspect.
The five things that keep a MacBook awake
1. Wake for network access (the #1 cause)
By default your Mac wakes to answer network requests — a shared printer, an iPhone hotspot, a router probe. Go to System Settings › Battery › Options (or Energy Saver on older macOS) and turn Wake for network access to Never. On desktops this hides under Power Nap and network options; set both off for testing.
2. Power Nap
Power Nap lets the Mac check mail, calendars, and iCloud while asleep — useful on a charger, maddening in a bag. Disable it in the same Battery › Options panel. If your macOS version has no toggle, it is off by default on battery.
3. Bluetooth “wake” devices
A Bluetooth mouse or trackpad can wake the Mac if it is jostled. Test by turning Bluetooth off for one night, or in System Settings › Bluetooth remove the accessory and re-pair only when needed.
4. A held-open power assertion (an app refusing sleep)
If the Mac never sleeps, an app is holding an assertion. Run:
pmset -g assertions
Look under PreventUserIdleSystemSleep and PreventUserIdleDisplaySleep for the offending process — common culprits are browsers playing background audio, video-call apps, download managers, and caffeinate. Quit that app (or reboot) and the assertion clears.
5. Scheduled or maintenance wakes
Time Machine, software updates, and powerd maintenance can wake the Mac. Check for a schedule with pmset -g sched and clear stray entries. A single reboot after a macOS update also resolves a surprising number of “won’t sleep” cases where the update left a service pinned awake.
Fast reset if you just want it to sleep tonight
- Toggle Wake for network access and Power Nap to off.
- Turn Bluetooth off.
- Run
pmset -g assertionsand quit any app holding sleep open. - On Apple silicon, no SMC reset exists — a normal restart replaces it. On Intel Macs, an SMC reset often cures a stuck power controller.
When it is NOT a settings problem
If the logs show no wake reason and it still will not sleep after the steps above — or the flip side, it opens to a black screen and needs a force-restart to wake — you may be looking at hardware. That black-screen, force-restart pattern is the classic won’t-wake-from-sleep failure, common on 2016–2019 MacBook Pros. In that case a repair rarely pays off, and trading toward a Mac that sleeps and wakes instantly is the cheaper path.
Related reading
- MacBook running slow? Here is why and how to fix it
- MacBook battery health, explained — runaway wakes drain a battery fast.
- Clamshell mode setup — if you want it awake lid-closed on a desk.
Shopping for a newer Mac that behaves? Our Apple clearance refurbished MacBooks ship free from Marion, Ohio with a one-year warranty.