By Ben | screenproblems.com | Updated: March 2026 | 8 min read
You open your MacBook Pro and there it is: one or more black horizontal lines running across the bottom of the screen. Before you book a repair, take two minutes to understand what is actually happening. In many cases the fix is free.
Black lines at the bottom of a MacBook Pro screen are almost always caused by one of three things: a failing display cable (known as Flexgate on 2016 to 2019 models), a corrupted graphics driver or macOS bug, or physical damage to the LCD panel.
Do this first: restart your MacBook. If the lines disappear after restart and come back as the device warms up, the cause is almost certainly a hardware cable issue, not software. If they disappear and stay gone, the cause was a temporary software glitch.
Step 1: Diagnose the Black Lines Before Doing Anything Else
Two minutes of correct diagnosis saves hours of wasted effort and potentially hundreds of dollars.
The External Monitor Test
Connect your MacBook Pro to an external monitor using HDMI or a USB-C adapter and check if the black lines appear on the external screen. If the external monitor shows a clean image, the problem is in your MacBook display, cable, or panel. If the lines also appear on the external monitor, the problem is in the GPU or macOS software.
The Screenshot Test
Press Command + Shift + 3 to take a screenshot and open the file in Preview. If the black lines are NOT visible in the screenshot, the issue is 100% hardware and software fixes will not help. If the lines ARE visible in the screenshot, the cause is a software or graphics rendering problem.
The Lid Angle Test
Open and close your MacBook lid slowly while watching the screen. If the black lines change, shift, or temporarily disappear at certain lid angles, a damaged display cable is the confirmed cause. This is the single most reliable way to identify Flexgate cable failure without opening the device.
Diagnosis Table
| What the Lines Do | Likely Cause |
| Only on internal screen, not external | Display cable or LCD panel damage |
| On both internal and external screens | GPU failure or macOS software bug |
| Visible in screenshots | Software or graphics driver issue |
| Not visible in screenshots | Physical hardware issue |
| Change when you move the lid | Flexgate display cable failure |
| Start at bottom and spread upward | Classic Flexgate progressive failure |
| Appeared after a drop | Physical LCD panel damage |
| Appeared after macOS update | Software or driver bug |
What Causes Black Lines at the Bottom of a MacBook Pro Screen?
1. Flexgate Display Cable Failure (Most Common)
This is the number one cause of black lines at the bottom of MacBook Pro screens, particularly on 2016 to 2019 Intel models. The display cable is routed through a tight hinge area and flexes every time you open and close the lid. Over 18 to 24 months of daily use, the cable develops micro-fractures and black horizontal lines start at the very bottom of the screen, gradually climbing upward over weeks or months.
Apple acknowledged this as a design flaw. The MacBook Pro Display Backlight Service Program covers qualifying models. Check support.apple.com to see if your MacBook qualifies for a free repair.
- Most affected models: MacBook Pro 13 inch and 15 inch from 2016, 2017, 2018, and 2019.
- Key sign: Lines that change position or disappear when you adjust the lid angle.
2. GPU or Logic Board Failure
When the GPU fails to render display output correctly, it produces black lines, artifacts, or distorted areas on screen. GPU-related lines typically appear on both the internal screen and any connected external monitor and are visible in screenshots, which distinguishes them from cable or panel failures.
Some 2013 to 2014 MacBook Pro models had GPU failures covered under Apple’s extended warranty program. Check support.apple.com for active repair programs for your model.
3. Physical Impact or Drop Damage
A drop or impact can crack the LCD panel or disconnect the display cable internally without visibly damaging the outer casing. Impact-related black lines tend to appear immediately after the drop, stay in a fixed position, and do not change with lid angle or spread progressively.
4. macOS Software or Driver Bug
Some macOS updates have introduced display rendering bugs that cause black lines, color distortions, or flickering artifacts. Software-caused lines almost always appear in screenshots and typically affect the entire screen rather than just the bottom section. A restart or macOS update usually resolves these.
5. Heat and Thermal Stress
Sustained high temperatures accelerate display cable degradation and can cause LCD panel components to expand unevenly, creating persistent display artifacts. If black lines appear primarily during heavy workloads and improve when the MacBook cools down, thermal stress is contributing to the problem.
How to Fix Black Lines at the Bottom of a MacBook Pro Screen
Work through these in order. Free software fixes first. Hardware repair last.
Fix 1: Restart Your MacBook
Hold the Apple menu and select Restart. A full restart resets the display driver and clears any temporary graphics glitch. If the lines disappear after restart and return as the device warms up, the cause is hardware. If they stay gone, a software glitch caused them.
Fix 2: Reset NVRAM
NVRAM stores display configuration settings and corrupted NVRAM can cause display artifacts including black lines.
- Intel MacBook Pro: Shut down. Turn on and hold Option + Command + P + R for 20 seconds. Release when you hear the second startup chime.
- Apple Silicon (M1, M2, M3, M4): A standard restart resets NVRAM automatically. No key combination needed.
Fix 3: Reset SMC (Intel Models Only)
The SMC controls power management, thermal management, and display output on Intel MacBook Pro models. This fix applies only to Intel models. Apple Silicon models do not have a separate SMC.
- Shut down your MacBook Pro.
- Hold Shift + Control + Option + Power button simultaneously for 10 seconds.
- Release all keys and power on normally.
Fix 4: Boot Into Safe Mode
Safe Mode disables third-party kernel extensions and uses basic display drivers, which can reveal whether a third-party app is causing the lines. Intel: hold Shift while booting. Apple Silicon: hold Power until startup options appear, then hold Shift and click Continue.
If the black lines disappear in Safe Mode, a third-party app or system extension is the cause. Uninstall recently installed apps to identify it.
Fix 5: Update macOS
Go to System Settings > General > Software Update and install any available update. Apple regularly patches display driver bugs in macOS point releases. If black lines appeared immediately after a macOS update, check the Apple Support Community for your specific model as Apple frequently issues a fix within days.
Fix 6: Check for Apple Repair Programs
Before paying for any repair, check if your MacBook Pro qualifies for a free or discounted fix. Many users pay hundreds of dollars out of pocket without realizing their MacBook qualifies for a free repair.
- MacBook Pro Display Backlight Service Program: Covers specific 2016 to 2019 models. Check support.apple.com.
- AppleCare Plus: Covers accidental display damage for a service fee of $99 per incident.
- Standard 1-year warranty: Covers manufacturing defects. Check coverage at checkcoverage.apple.com.
Fix 7: Professional Screen Replacement
If all software fixes fail and no repair program covers your device, a screen replacement is the final solution. Third-party certified shops typically charge 30 to 40% less than Apple. Always ask for a written warranty on parts and labor before approving any repair.
| MacBook Pro Model | Apple Service Fee | Third-Party Shop |
| MacBook Pro 13 inch (M2/M3) | $299 to $399 | $180 to $260 |
| MacBook Pro 14 inch (M3/M4) | $399 to $499 | $240 to $320 |
| MacBook Pro 16 inch (M3/M4) | $499 to $599 | $300 to $400 |
| Intel 13 inch (2016 to 2020) | $199 to $349 | $120 to $220 |
| Intel 15/16 inch (2016 to 2019) | $299 to $499 | $180 to $320 |
Which MacBook Pro Models Are Most Affected?
| Model | Main Cause | Apple Program? |
| MacBook Pro 2016 to 2019 (Intel) | Flexgate cable failure | Yes — check support.apple.com |
| MacBook Pro 2013 to 2014 (Intel) | GPU failure | Check for active programs |
| MacBook Pro 2020 to 2022 (M1/Intel) | macOS bugs, rare hardware | Standard warranty only |
| MacBook Pro 2023 to 2024 (M2/M3/M4) | Software or macOS driver bugs | Standard warranty only |
If your MacBook is a 2016 to 2019 model and shows lines that start at the bottom and spread upward, check the Apple repair program immediately before spending money on a repair.
How to Prevent Black Lines on MacBook Pro Screen
- Do not force the lid open or closed. Open the MacBook with one hand supporting the base to reduce hinge stress.
- Keep macOS updated. Display driver patches are released regularly.
- Avoid blocking the vents. Overheating accelerates display cable degradation.
- Use your MacBook on hard flat surfaces rather than soft surfaces like beds or sofas that block airflow.
- Do not use the MacBook in extreme temperatures. LCD components are sensitive to heat and cold.
- If you carry the MacBook in a bag, use a padded sleeve to protect it from pressure and impacts.
Frequently Asked Questions
Why do black lines appear at the bottom of my MacBook Pro screen specifically?
The bottom of the screen is where the display cable exits the hinge and connects to the LCD panel. On 2016 to 2019 models, this cable is routed through a very tight path and wears out faster than the rest of the display assembly. This is why lines almost always start at the bottom and spread upward over time.
Can black lines on a MacBook Pro screen fix themselves?
Software-caused lines can resolve after a restart or macOS update. Hardware-caused lines do not fix themselves. A Flexgate cable failure will progressively worsen until the screen becomes completely unusable if left unrepaired.
Is it safe to keep using a MacBook Pro with black lines on the screen?
The device is safe to use as long as the lines are not accompanied by overheating, unexpected shutdowns, or the screen going completely black. However if the cause is Flexgate, the lines will worsen over time. It is better to address the issue sooner to avoid a complete display failure.
Does Apple cover black lines under warranty?
Manufacturing defects are covered under the standard one-year warranty. The Flexgate issue on 2016 to 2019 models is covered under Apple’s extended Display Backlight Service Program at no charge for qualifying devices. AppleCare Plus covers accidental damage for a $99 service fee. Always check support.apple.com and checkcoverage.apple.com before paying for any repair.
How much does it cost to fix black lines on a MacBook Pro screen in 2026?
If covered by an Apple repair program: free. With AppleCare Plus: $99 service fee. Out of warranty at Apple: $199 to $599 depending on the model. At a third-party certified shop: $120 to $400. Always verify repair program eligibility before paying out of pocket.
Final Verdict
Black lines at the bottom of a MacBook Pro screen are almost always caused by Flexgate cable failure on 2016 to 2019 models, or a software glitch that clears after a restart.
Start with the external monitor test and the screenshot test to confirm whether the cause is hardware or software. Try the free fixes: restart, NVRAM reset, SMC reset, and Safe Mode.
Most importantly: check apple.com/support for active repair programs before spending a dollar. Many MacBook Pro users with this exact problem qualify for a free repair and never know it.
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| About the AuthorBen is the founder of screenproblems.com, a resource dedicated to diagnosing and solving mobile and computer display issues.All content is written without brand sponsorship. Every recommendation is based on what actually works. |