Lines on your MacBook screen come in all shapes: thin vertical lines, coloured horizontal bars, or a strip that flickers. We regularly see them on both the MacBook Pro and the MacBook Air. The cause can be in the screen itself, in the cable to the screen or in the graphics chip on the logic board. This article explains how a few simple tests show where it is, and what you can do about it.
Blue Apple repairs MacBook screens in Amsterdam. Lines are one of the most common screen complaints we see.
Test 1: take a screenshot
Press Shift + Command + 3 and open the screenshot on your desktop. Look at that image on another device, such as your phone.
- The lines are also in the screenshot: the image is already made wrong. Then it is the software or the graphics chip.
- The lines are not in the screenshot: the image is fine, but the screen or cable displays it wrongly. That is the most common situation.
Test 2: connect an external monitor
Connect your MacBook to a TV or monitor. If there are no lines there, the problem is in the MacBook's screen or the cable to it. If you see the same lines there, that points to the graphics chip or the software.
Test 3: move the screen
Slowly open the screen further and back again. Do the lines change, appear only from a certain angle, or does the screen suddenly go black? Then the cable between the logic board and the screen is damaged. On MacBook Pro models from about 2016 to 2018 that was a known problem: the thin cable wears from opening and closing.
The most common causes
- Pressure on the screen. A MacBook closed with something in between (a pen, earbuds, a thick camera cover), or carried in a full bag. The glass often looks intact, but the layer underneath is damaged. You then usually see vertical lines or a dark patch that spreads.
- A drop or knock. Even without a crack in the glass the screen can be damaged inside.
- Liquid. Liquid running in at the hinge attacks the screen connection. Read liquid spilled on a MacBook.
- A worn screen cable, as in test 3 above.
- The graphics chip. Especially on older MacBook Pro models with a separate graphics card it can fail. Then you also see the lines on an external monitor.
What you can try yourself
- Restart the MacBook.
- Install the latest macOS update.
- Start up in safe mode. If the lines are gone there, a program or setting is the cause.
- On an Intel MacBook: reset the NVRAM (hold Option + Command + P + R during startup).
If this does not help and the lines are not in the screenshot, it is almost certainly hardware. Do not press on the screen "to test": that often makes the damage worse.
What we do at Blue Apple in Amsterdam
We test with an external monitor and measuring equipment whether the problem is in the screen, the cable or the logic board. Usually the solution is a new screen. You hear beforehand which options there are for your model and what it costs. More on our page about MacBook screen repair. If your screen is mainly black or flickering, read MacBook screen black or flickering.
Frequently asked questions
Do lines on a MacBook screen go away by themselves?
Almost never. Lines from damage to the screen usually get gradually worse.
Can I still use my MacBook with lines?
Often yes, possibly with an external monitor. Make sure you have a backup in any case.
Why do the lines appear only at a certain angle?
Then usually the cable to the screen is damaged. That cable bends when you open the screen.
