Black lines on a MacBook Pro screen are almost always a hardware fault in the display panel, its cable or the graphics hardware, not a software bug. If the lines also appear in screenshots or on an external monitor, the cause is different. Most confirmed panel faults mean replacing the display assembly, so get a quote first.
Key takeaways
- Horizontal or vertical black lines that stay put usually mean panel or cable damage. Lines that flicker or move can point to graphics or logic board faults.
- Do the screenshot test and the external monitor test before spending money. They separate display faults from graphics faults.
- The 2016 MacBook Pro line has a known display backlight cable weakness often called flexgate. Check Apple's current program status for your model.
- Pressure damage from a closed lid, a stray cable or a pen on the keyboard can crack the panel on any model, including Apple silicon.
- Repair or replace depends on the repair quote compared with the Mac's value. See the cost table and treat the figures as estimates.
What black lines on the screen usually mean
Black or dark lines, bars or patches can be thin or thick, horizontal or vertical, and may appear after a knock, after waking from sleep or gradually over weeks. They are rarely caused by macOS. The display is a layered panel, and each line usually corresponds to a failed row or column of pixel drivers, a loose connection between layers, or a signal problem on the cable from the logic board.
Different patterns point to different causes:
- A single thin vertical line that never moves. Typically a failed column in the panel. It often grows or multiplies over time.
- Several vertical lines or bars on one side. Often the panel's connection or driver chip, or damage from lid pressure.
- Horizontal lines that flicker. Can be a display cable or graphics fault, especially if they change when you flex the lid.
- Black patches or an ink-like stain. Cracked liquid crystal layers, usually after impact or pressure.
- Uneven bright patches along the bottom (stage-light effect), then a dark screen. A flexgate-style backlight cable fault on certain 2016 MacBook Pro models.
Step-by-step: confirm where the fault is
These checks are free and take about ten minutes.
Step 1: Look closely with a plain background
Open a blank white document or a full-screen white image, then a black one. Lines that stay in identical positions on both backgrounds are physical. Note whether they are inside the picture or follow the edge of the panel. Take a photo with your phone for the repair provider.
Step 2: Take a screenshot
Press Shift, Command and 3 and open the saved image in Preview. A screenshot is created in software before the signal reaches the panel. If the lines appear only on the live display and not in the screenshot, the fault is in the panel, the cable or the display path. If the lines appear in the screenshot, suspect graphics or software.
Step 3: Connect an external monitor
Plug the Mac into an external monitor or TV with a known good cable. If the external picture is clean while the built-in screen has lines, the logic board and graphics are working, and the problem is the built-in display. If the external monitor shows lines or artefacts too, the graphics hardware or logic board is the likely cause, which is more costly.
Step 4: Look at the hinge and lid flex
Slowly open and close the lid while watching the lines. If they change with lid angle, flicker or disappear at certain positions, the display cable or hinge connection is involved. Do not force the lid or flex it repeatedly, as that can tear a worn cable.
Step 5: Run Apple Diagnostics and rule out software
Run Apple Diagnostics: on Apple silicon, shut down, hold the power button until startup options appear, then press Command and D. On Intel Macs, restart and hold D. The test is limited for display issues, but it can flag graphics or board faults. Then boot into Safe Mode (Apple silicon: hold power, choose disk, hold Shift, Continue in Safe Mode; Intel: hold Shift at startup). If the lines persist at the Apple logo and in Safe Mode, software is not the cause.
Step 6: Check for physical damage
Look at the outside and inside of the lid. A small dent, a pressure mark on the glass, or a faint ring in the screen where a pen, earbuds case or charger sat between the keyboard and the screen when the lid was closed are classic causes of cracked panel layers. Thin modern MacBooks have very little clearance when closed, so even a small object or a heavy bag can damage the panel. Damage of that type is not normally covered by a standard warranty, but check the terms of your coverage and of any extended plan.
Model-specific notes
2016 MacBook Pro (flexgate)
The 2016 13-inch and 15-inch MacBook Pro models use a very thin cable that connects the display to the board and runs around the hinge. Repeated opening can wear the cable, which first shows as uneven lighting along the bottom edge, often called the stage-light effect, and then as a dead backlight. The screen can still show a faint image if you shine a torch on it. This is a backlight fault, not black lines, but people often describe it as dark bands. Apple has run a service program for part of this range in the past. Check Apple's current program status for your model and serial number before you pay for any repair. Be aware that some third-party repair quotes for this fault include only a cable, while a new display assembly may be needed.
2017 to 2019 Intel MacBook Pro
The cable design was revised on later models, so classic flexgate is less likely, but black lines, patches and flicker after impact or pressure remain possible. These models also have discrete AMD graphics in many 15-inch versions, so a graphics fault can produce lines that appear on an external monitor too.
Apple silicon MacBook Pro and Air (M1 and later)
Lines on these models are most often a physical panel problem. Pressure from objects trapped between the keyboard and the lid, a knock on the corner, or flexing the lid by carrying the Mac by its screen can crack the panel. The graphics are integrated into the main chip, so a clean screenshot and a good external monitor with a bad internal panel strongly indicate a display assembly fault.
Older Intel MacBook Pro, 2012 to 2015
Some retina models of that period developed image retention and coating damage on the display. Black lines are mostly panel or cable failures here too, though parts are cheaper and more widely available.
Repair or replace: how to decide
There are really three options: replace the display assembly, repair the cable or connector if that is the only fault, or replace the Mac. Use the checks below.
- Confirm the cause. If the external monitor and screenshot are clean, the display is the issue. A good technician can then test with a known good panel.
- Get a written quote for the display assembly. This is the usual fix for panel lines. Quotes vary considerably.
- Compare with the Mac's value. If the quote is more than about half what the Mac would sell for, weigh a repair against a replacement. A recent Apple silicon Mac in good order usually justifies the repair.
- Check coverage. A manufacturing defect on a young Mac may be covered by warranty or consumer law. Accidental damage generally is not unless you bought a plan that includes it.
- Plan for a backup first. The Mac is usually still usable. Copy your files before it goes in for repair. If the display is unreadable, use an external monitor.
Using the Mac with a damaged panel is not dangerous, but lines can spread, and a cracked panel can leak liquid crystal. If the glass is cracked, do not press on it or clean it with liquid. Our MacBook repair cost guide for Canada gives more context on what the common repairs cost.
What does repair typically cost?
The display is often the most expensive single part of a MacBook other than the logic board. Costs depend on the model, whether the assembly includes the lid, and the provider.
| Repair | USD | GBP | CAD | AUD |
|---|---|---|---|---|
| Diagnosis only | $0 to $100 | £0 to £80 | CA$0 to CA$130 | A$0 to A$150 |
| Display cable or backlight cable repair | $150 to $450 | £120 to £360 | CA$200 to CA$600 | A$230 to A$680 |
| Display assembly replacement, Air or 13-inch Pro | $350 to $750 | £280 to £600 | CA$470 to CA$1,000 | A$530 to A$1,130 |
| Display assembly replacement, 14-inch or 16-inch Pro | $550 to $1,000 | £440 to £800 | CA$740 to CA$1,350 | A$830 to A$1,500 |
| Graphics or logic board repair | $500 to $1,200 | £400 to £960 | CA$670 to CA$1,600 | A$750 to A$1,800 |
Typical ranges, estimates only. Prices vary by model, provider and location, and they change over time. Always get a written quote.
Our MacBook screen replacement page explains what a replacement involves and how it is quoted in Montreal.
What not to try at home
- Do not press on the glass or flex the lid to see if the lines change repeatedly. You can crack the panel or tear the display cable.
- Do not heat the screen with a hair dryer. Some old videos suggest this, and it can damage the layers.
- Do not open the lid beyond its normal range or remove the display unit without the right tools, particularly on Apple silicon models where the cable and the hinge are integrated.
- Do not clean the screen with solvents or liquid sprays. Use a dry microfibre cloth, lightly dampened with water if needed.
Tips to avoid damage next time
- Close the lid on nothing but air. Remove camera covers, pens, cables or cards from the keyboard.
- Carry the Mac in a padded sleeve and avoid squeezing it into overfull bags.
- Open the lid by the centre edge with one hand on the base, and avoid lifting the Mac by the screen.
- Avoid heavy items on top of a bag that contains the Mac.
When to call a professional
See a technician if the lines persist at startup and in Safe Mode, if they appear on an external monitor, if the backlight has dimmed or shows uneven patches, if the glass is cracked, or if the problem began after a drop, pressure or liquid. For liquid events, read water damaged MacBook repair and act quickly. A technician can confirm whether the display, cable or board is at fault before you spend money on parts. Our Mac repair service covers diagnosis. If you are not near Montreal, a remote session can rule out software and help with a backup, using remote Mac support in Canada or remote computer repair in the USA.
Not sure what is wrong? Get a diagnosis first.
Our certified tech can connect remotely, check your software, drivers and backups, and tell you honestly whether the problem needs a hands-on repair.
Frequently asked questions
Why does my MacBook Pro screen have black lines?
Black lines are usually caused by a damaged display panel, a worn or loose display cable, or occasionally a graphics or logic board fault. Screenshots and an external monitor help tell which.
Can black lines on a MacBook screen be fixed without replacing the screen?
Sometimes, if the fault is a loose or worn cable or connector. If the panel itself is damaged, the usual fix is a display assembly replacement.
Is the black line problem related to flexgate?
Flexgate affects the backlight cable on some 2016 MacBook Pro models and shows as uneven lighting and a dim screen. Black lines on a lit screen more often indicate panel damage. Check Apple's current program status for your model.
Will the lines get worse over time?
They often do. A single thin line can grow or multiply, and a pressure crack may spread. Back up your files and get a quote before the screen becomes unusable.
Is it worth replacing the screen on an older MacBook Pro?
It depends on the quote and what the Mac is worth. On a newer Apple silicon model it usually is. On an older Intel machine with other problems, compare the cost with a replacement.