Mac Screen Keeps Going Black? Here's How to Stop It

You’re typing an email and the screen blinks black for half a second. A minute later it happens again. Then again. Sometimes it’s a quick blackout; other times the screen stays black for three or four seconds and you can hear macOS still running before it comes back.

This is different from a totally-stuck black screen. The display is mostly working — it just intermittently fails for a moment, then recovers. The cause depends on whether you’re on built-in display only or also driving an external.

What’s blacking out — built-in, external, or both?

Pay attention to which screen drops out:

• Just the external: cable, hub, or EDID issue. Most common.
• Just the built-in MacBook: display cable inside the lid, GPU swap glitch (Intel), or graphics driver issue.
• Both at the same time: GPU-level event — the whole graphics stack is briefly going down.
• Alternating between displays: graphics-switching issue (Intel) or display arrangement state corruption.

That tells you where to focus.

Try a different cable / port (external displays)

If only the external is dropping out:

• Replace the cable. HDMI cables are especially prone to going bad — even brand-new ones often can’t handle 4K 60Hz long-term.
• Bypass any USB-C hub. Plug the monitor directly into the Mac.
• Try a different port on the Mac. Thunderbolt ports are paired; one pair can act up while the other is fine.
• Try a different cable type — DisplayPort instead of HDMI, or vice versa.

If swapping the cable or skipping the hub fixes it, you’ve found the cause.

Lower the refresh rate

Mismatched or marginal refresh rate is a top cause of intermittent blackouts. macOS can pick a refresh rate the cable barely supports, and any signal interruption — a power flicker, a USB device drawing extra current — drops the link briefly.

System Settings → Displays → click the affected display → drop the refresh rate to 60Hz if you’re at 120Hz or higher. For 4K monitors over HDMI 2.0, even 60Hz is at the cable’s limit; try 30Hz as a test. If blackouts stop at lower refresh, the cable can’t handle full bandwidth.

Disable automatic graphics switching (Intel)

On Intel MacBook Pros with discrete GPUs (15”/16” 2016–2019), the swap between integrated Iris/UHD and discrete Radeon Pro can produce a visible blackout. The screen briefly dies during the GPU handoff.

System Settings → Battery → Options → turn off “Automatic graphics switching.” The Mac runs on the discrete GPU full-time. Battery life suffers, but blackouts vanish.

This doesn’t apply to Apple Silicon — there’s only one GPU, no swap.

Reset corrupted display prefsSweep can wipe and rebuild stale display preference files when those are the cause. Get Sweep free →

Update macOS

GPU drivers ship inside macOS point releases. Several documented blackout regressions in early Sonoma builds were fixed in 14.4 and later. Sequoia has had its own quirks at launch that subsequent updates addressed.

System Settings → General → Software Update — install pending updates.

Check for sleep/wake bugs

If the blackouts only happen after waking from sleep, you’re hitting a sleep/wake glitch. This is a known annoyance with certain Mac + display combinations.

Workarounds:

• Disable “Wake when display is opened” testing flag if it’s set somehow.
• In System Settings → Lock Screen, change “Turn display off when inactive” to a longer time so the display sleeps less often.
• For external displays, disable “Power Nap” which keeps some background activity going during sleep that can confuse re-wake.

A persistent sleep/wake blackout pattern usually points to a USB-C hub or dock that doesn’t handshake cleanly on wake. Plug the monitor directly into the Mac as a test.

EDID issues

External monitors broadcast their capabilities through EDID data. Bad EDID can cause macOS to try a configuration the monitor can’t actually maintain — the link drops briefly when the monitor refuses a frame, then reconnects.

Symptoms of EDID-related blackouts:

• Always happens shortly after wake from sleep.
• Specific to one monitor; another monitor on the same cable doesn’t drop.
• Switching from HDMI to DisplayPort (or vice versa) fixes it.

BetterDisplay (free) can override the EDID with a clean version. That’s the fix when the monitor’s firmware itself is the issue.

Skip the manual huntSweep clears the cached configs and broken plists that mess with macOS. Download Sweep free →

Check power delivery

If you’re using a USB-C hub or dock that’s also passing power to the MacBook, a power negotiation hiccup can cause everything to drop briefly — including the display.

Test: plug the MacBook charger directly into the laptop, separate from the hub, and run video to the monitor through a different path (or directly to the Mac). If blackouts stop, the dock’s power delivery was the issue. Either upgrade the dock to one with cleaner power handling (CalDigit, OWC, Anker Apex are generally fine), or run power separately.

Reset display preferences

When display config gets corrupted, you can get blackouts that no settings change fixes. Files at ~/Library/Preferences/ByHost/com.apple.windowserver.* and related.

Manual reset: quit System Settings. Finder → Cmd + Shift + G → ~/Library/Preferences/ByHost/. Move all com.apple.windowserver files to Desktop. Restart.

You’ll lose display arrangements and per-display settings. Worth it if blackouts are frequent.

ColorSync profile issues

Rarely, a bad ICC profile can cause the system to send a frame the display can’t accept, producing a brief blackout while it negotiates a fallback.

Open ColorSync Utility (Applications → Utilities → ColorSync Utility). If a third-party profile is active, switch back to stock Apple in System Settings → Displays → Color Profile. Check if blackouts continue.

Apple Silicon vs. Intel

Apple Silicon Macs are generally more reliable on this front. No graphics switching to glitch. Stricter cable validation upfront — a cable that’s marginal will often fail to negotiate at all rather than working then failing intermittently.

Intel Macs with discrete GPUs are prone to blackouts during graphics swap. Disabling automatic graphics switching is the first thing to try. Older Intel Macs (2016–2019) also have well-documented dGPU issues that produce intermittent blackouts as the dGPU degrades.

When it’s hardware

Persistent blackouts that survive software fixes:

• Intel MacBook Pro 2016–2019: dGPU is failing. Apple has had repair programs for some specific models — check Apple support.
• Any MacBook: display cable inside the hinge wearing out. Symptoms include blackouts that change with lid angle, or that worsen as the lid is opened/closed more.
• External monitor: monitor’s HDMI/DisplayPort controller is failing. Test the monitor on another computer to confirm.

What Sweep handles

For software-side blackout issues, Sweep helps by:

• Clearing corrupted display preferences in one click.
• Wiping cached EDID and color profile data from previously-connected displays.
• Removing leftover graphics-related plists from uninstalled apps.

For hardware blackouts (cable, GPU, dock), Sweep can’t help — you need to swap hardware. For software causes, it’s the fastest way to clean up what you’d otherwise hunt for in ~/Library.

There’s a faster waySweep does this cleanup in seconds. Try Sweep free →

Identify which screen is dropping. Swap cables and bypass hubs. Lower refresh rate. Disable graphics switching on Intel. Update macOS. Reset display prefs. Most blackout cases trace back to one of those — and the cable is the single most common cause.