Fix lines on your MacBook screen in simple steps
It can be really alarming when you’re dealing with lines on a MacBook screen. I’ve dealt with flickers, pink stripes, and the classic thin horizontal lines that appear right when a deadline hits.
The trick is to separate software glitches from physical screen trouble fast, then work through a short list in the right order.
Here’s everything I learnt along the way.
MacBook Pro lines on the screen: what causes them?
From all my research, I discovered lines essentially come in under three topics:
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Software: a hiccup in graphics services, a buggy app, old macOS, or a corrupted cache.
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Hardware: a damaged LCD panel, a frayed display cable in the hinge, or a failing logic-board path.
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Environment: Heat. When the GPU gets too hot, it can show up as bands or random lines.
The screenshot test
Take a screenshot with Shift - Command - 4.
If the lines appear in the screenshot file and you see them on another device, that points to software or GPU output.
If the screenshot looks perfect elsewhere, the problem lies with your physical display system.
|
Do lines appear inside screenshots? |
Likely cause |
What to try first |
|
Yes |
Software or GPU pipeline |
Restart, update macOS, cache cleanup, safe mode |
|
No |
Screen panel or display cable |
External monitor test, cool-down, Apple Diagnostics |
Immediate software fixes & maintenance
Work your way through these quick horizontal lines on the MacBook screen fixes.
1. Restart the Mac
A clean restart resets the Windows Server state, GPUs, and drivers. If lines disappear and stay gone, you were looking at a transient glitch. Head to your Mac's main menu and hit Restart.
2. Update macOS and your apps
Go to System Settings> General > Software Update.
Not many people realise, but patches for graphic glitches get rolled out with system updates. Update heavy hitters like Chrome, Lightroom, and Zoom, which can trigger rendering quirks, so it’s wise to always keep your Mac running the latest macOS.
3. Clear clutter that confuses graphics
Corrupted caches and swollen logs can sometimes cause rendering issues. I run CleanMyMac > Cleanup to remove safe system junk. CleanMyMac is a macOS maintenance utility, and in my testing, this light clean has cleared banding that returned after every reboot until I tidied caches. You can test it for 7 days free — get your trial here.
4. Safe mode check
Shut down. On Apple silicon, press and hold the power button until Options appears, then choose your startup disk while holding Shift to enter safe mode.
On Intel, shut down your Mac and then press and hold Shift immediately while turning it back on. Do not release Shift until you see the login window.
If lines vanish in safe mode, third-party extensions or login items are likely involved.
Monitoring your Mac’s GPU health
Heat can be another reason why lines appear on your screen when the GPU is stressed.
If you suspect heat is a factor for your device, here are some quick action steps to follow:
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Give your Mac some airflow. Move off a blanket or couch and elevate the rear edge on a stand.
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Close heavy apps. Video timelines, 4K streams, and dozens of animated tabs push the GPU.
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Check for dust. Check your Mac for dust buildup and follow the guidance from Apple on how to safely remove it. Dust can block vents and prevent airflow, too.
I keep the CleanMyMac Menu app in the menu bar because it shows live CPU temperature and load at a glance. If lines appear only when temperatures spike into the red, you are looking at thermals, not a broken LCD. Cooling the machine will help.
Advanced system resets for vertical lines on MacBook screen
If you’re still having issues with your screen after updates and a cleanup, here are some more advanced fixes.
1. NVRAM or PRAM (Intel only)
Shut down. Power on and immediately hold Option - Command - P - R for about 20 seconds. This resets display resolution, color profile references, and some video settings.
2. SMC reset
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Intel: Shut down. On T2 models, press and hold Control - Option - Shift on the right side for 7 seconds, keep holding and press power for 7 more, release, wait, then power on. Other Intel models have slightly different SMC combos.
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Apple silicon: There is no separate SMC reset. A full shutdown, wait 30 seconds, then start normally, accomplishes the same thing.
If you have time, repeat the safe mode test after these resets. A clean boot that renders without lines points back to login items, menu bar utilities, or an extension.
Hardware deep-dive: External monitors and cables
This is where you decide if the MacBook lines on the screen are caused by the screen assembly or the system.
1. External monitor test
Connect to a display or TV with USB-C or HDMI and mirror the screen.
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Lines only on the MacBook panel, not the external display, point to the LCD or flex cable.
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Lines on both the mean system output are at fault.
2. Lid angle
If tilting the lid changes or fixes the lines, you are likely seeing wear in the thin ribbon cable that passes through the hinge. That long-term strain is what people nicknamed Flexgate. It starts as intermittent horizontal lines or a “stage light” fades near certain angles.
3. Run Apple Diagnostics
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Shut down
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For a Mac with Apple silicon, press and hold the power button until you see Startup Option. Then, release the power button and press and hold Command + D.
On an Intel-based Mac, press and hold D while restarting your Mac. -
Note any reference codes. (You may see codes in the VFD00x family that a Genius can translate, so take note).
At this stage, it’s time to back up. If a cable is failing, it tends to get worse.
When nothing works
Some symptoms are not software, and if nothing in this article has helped so far, it’s time to book your Mac in at an official repair center.
If you’ve got any of these issues, make your appointment fast:
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Physical damage: cracks, pressure “ink blotches,” or a rainbow smear that never moves.
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Persistent lines after a macOS reinstall, safe mode, and external display checks.
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Angle-dependent lines that return every time you open the lid to a specific position.
I hope this article has helped you diagnose what’s causing the lines on your MacBook screen and fixed the issue.