As the owner of a tech repair shop, I’ve helped countless MacBook users frustrated by lines on their screens. Whether it’s flickering stripes, colored bars, or a display that cuts out, this issue can disrupt your workflow.
In my years of experience, I’ve seen this problem stem from hardware like faulty graphics cards or LCDs, or even specific design flaws like the 2016 MacBook Pro’s Flexgate issue. In this guide, I’ll explain why lines appear on your MacBook screen, why graphics cards fail, and how to troubleshoot or fix the problem.
What’s Causing Lines on Your MacBook Screen?
Lines on a MacBook screen can result from hardware failures or, less commonly, software glitches. Here are the most frequent causes based on my repair experience:
1. Faulty Graphics Card (GPU)
The graphics processing unit (GPU) renders everything you see on your screen. When it fails, you might notice horizontal or vertical lines, flickering, or distorted colors. This is a common issue, especially in older MacBooks.
Why do graphics cards fail?
- Overheating: Tasks like gaming, video editing, or running heavy software generate heat. MacBooks’ slim designs often struggle to cool the GPU, causing damage over time.
- Manufacturing Defects: Some models, like the 2011 and 2012 MacBook Pros with AMD GPUs, had faulty chips prone to failure, leading to lines or blank screens.
- Aging Solder Joints: The connections between the GPU and logic board can degrade, causing intermittent display issues.
- Power Surges: Though rare, voltage spikes can damage the GPU’s circuitry.
Diagnosis Tip: Connect your MacBook to an external monitor via HDMI or USB-C. If lines appear on the external display, the GPU is likely the culprit. If the external screen is clear, the issue is with the MacBook’s display or its connections.
2. Damaged LCD Panel
A faulty or damaged LCD can cause lines, dead pixels, or flickering. Physical damage from drops or pressure, or even wear over time, can disrupt the screen’s internal connections.
Symptoms:
- Lines only appear on the MacBook’s built-in screen, not an external monitor.
- Flickering or lines that shift when you press on the display.
- Persistent lines after restarting.
3. 2016 MacBook Pro Flexgate Issue
If you have a 2016 MacBook Pro (13-inch or 15-inch), you might be dealing with a design flaw called Flexgate. The display’s flex cable, which connects the screen to the logic board, is too short and wears out with repeated lid opening. This leads to:
- Horizontal lines at the bottom of the screen.
- Flickering or “stage lighting” effects.
- Screen blackout when the lid is fully opened.
Apple launched a repair program for affected 2016 models, but coverage is limited. A professional repair shop can confirm if this is your issue.
4. Loose or Damaged Display Cable
Beyond Flexgate, a loose or frayed display cable can disrupt the signal between the GPU and screen, causing lines or flickering. This often happens in MacBooks that have been mishandled or frequently opened.
Symptoms:
- Lines that change when adjusting the screen angle.
- Intermittent display problems.
5. Software Glitches
Software issues, like outdated graphics drivers or corrupted macOS files, can mimic hardware problems. These are less common but easier to fix.
Symptoms:
- Lines disappear when booting in Safe Mode (hold Shift during startup).
- Issues began after a macOS update or app installation.
How to Troubleshoot MacBook Screen Lines
Before seeking professional help, try these steps to identify or resolve the issue:
- Restart Your MacBook: Click Apple Menu > Restart to clear temporary glitches.
- Update macOS: Go to Apple Menu > System Preferences > Software Update to ensure your graphics drivers are current.
- Reset the SMC: The System Management Controller manages display functions. To reset:
- For T2 chip models: Hold Control + Option + Shift + Power for 7 seconds.
- For older models: Hold Shift + Control + Option + Power for 10 seconds.
- Run Apple Diagnostics: Shut down, then hold the D key while powering on to check for hardware issues. Note any error codes.
- Test with an External Monitor: If lines appear on an external display, the GPU is faulty. If not, the issue is likely the screen or cable.
- Check for Overheating: Use apps like iStat Menus to monitor temperatures. If your MacBook exceeds 192°F, let it cool and ensure proper ventilation.
When to Get Professional Repairs
If these steps don’t fix the issue, you’re likely dealing with a hardware problem. A professional repair shop can diagnose whether it’s a bad GPU, faulty LCD, or Flexgate-related cable issue. Here’s what repairs might involve:
- GPU Repair: Reworking or replacing a GPU can cost $300–$500, depending on the model.
- LCD Replacement: A new screen typically costs $400–$700.
- Flexgate Repair: For 2016 MacBook Pros, cable or screen replacement costs $200–$400 if not covered by Apple’s program.
- Data Protection: Always back up your data before repairs. Tools like EaseUS Data Recovery Wizard for Mac can help.
At Tech Medic, we specialize in MacBook repairs, using high-quality parts and offering competitive pricing. Bring your device to us for a free diagnosis.
Preventing Future Screen Issues
To keep your MacBook’s display in top condition:
- Avoid Overheating: Use your MacBook on a hard, flat surface and clean vents regularly.
- Handle Carefully: Prevent drops or pressure on the lid to protect the LCD and cables.
- Keep Software Updated: Regular macOS updates prevent driver-related issues.
- Consider AppleCare: Extended warranties can reduce repair costs.
Get Your MacBook Fixed with Tech Medic
Lines on your MacBook screen can be frustrating, but they’re often fixable. Whether it’s a bad graphics card, a faulty LCD, or the 2016 Flexgate issue, a skilled technician can restore your device. At Tech Medic, we’ve repaired hundreds of MacBooks and offer expert service at affordable rates. Visit Techmedivt.com to learn more or schedule a repair today!
