Why Do Horizontal Lines Appear on iMac Screens?
Horizontal lines may look like a minor glitch, but they often point to deeper hardware or software issues. Here are some of the main causes:
- Graphics card issues: A faulty or overheating GPU can cause screen lines.
- Loose or damaged display cable: If the cable connecting the display is loose, it can result in visible lines.
- Software glitches: macOS updates or driver problems may trigger temporary display errors.
- Physical damage: A drop, impact, or exposure to moisture can also lead to display issues.
- Overheating in Dubai’s climate: With high temperatures, overheating can damage internal components over time.
First Steps to Troubleshoot
Before rushing to a repair center, you can try a few simple fixes at home.
1. Restart Your iMac
Sometimes, a simple restart clears temporary glitches. Shut down your iMac and restart after a few minutes.
2. Run Apple Diagnostics
Hold the D key while restarting your iMac. Apple Diagnostics will run a quick test to identify hardware issues.
3. Update macOS
Outdated software can cause display issues. Go to System Settings > General > Software Update and install any available updates.
4. Reset NVRAM/PRAM
- Shut down your iMac.
- Hold Option + Command + P + R keys while turning it on.
- Keep holding until you hear the startup sound twice.
5. Check for External Devices
Sometimes, external devices like printers or USB hubs can cause conflicts. Disconnect all accessories and test again.
When to Seek Professional Repair
If the above steps do not solve the problem, the issue might be hardware-related. Here is when you should contact an expert in Dubai:
- Lines appear even after macOS updates.
- The problem worsens when the iMac heats up.
- The screen flickers along with the lines.
- You notice discoloration or dark patches on the display.
In such cases, professional repair services can run deeper diagnostics and fix the root cause. Many users in Dubai rely on trusted repair shops for quick solutions, especially when their iMac is out of warranty. For reliable support, Azizi Technologies UAE offers expert repair services tailored to Apple devices.
Preventing Horizontal Lines on Screen of iMac 24 2021
Prevention is always better than repair. Here are some tips to keep your iMac safe in Dubai’s environment:
- Avoid overheating: Keep your iMac in a cool, air-conditioned space.
- Regular cleaning: Dust can block ventilation, leading to hardware stress.
- Use surge protectors: Power fluctuations can damage display components.
- Handle with care: Avoid sudden movements or impacts on the desk.
- Update regularly: Always keep macOS up to date to prevent software conflicts.
Quick Comparison of Causes and Solutions
| Cause | Solution |
| GPU or graphics card issue | Run diagnostics; may need replacement |
| Loose display cable | Professional repair to reconnect or replace |
| Outdated software | Install the latest macOS updates |
| Overheating | Improve ventilation; keep the device in a cool area |
| Physical damage | Screen replacement or professional repair |
Final Thoughts:
Horizontal lines on the screen of an iMac 24″ (2021) can be stressful, but not every case is serious. Sometimes a simple restart, macOS update, or diagnostics test can solve the issue. When these steps do not work, it usually means there is a hardware problem that needs expert repair.
In Dubai, many professionals rely on their iMacs for both work and creativity, so keeping them in perfect condition is important. That is where our team at Azizi Technologies UAE comes in. We use our experience to quickly identify the cause, whether it is a display issue, a GPU fault, or a logic board problem. With our experts handling the repair, you can be confident your iMac will return to delivering sharp and smooth visuals.
