8 Causes of Lines on Security Camera and How to Fix Them​
If you see horizontal or vertical lines on security camera feed, it is a classic analog interference issue. These visual distortions appear as moving bars, flickering stripes, or faint rolling bands. They make footage difficult to view and record, especially at night.
Both horizontal and vertical lines share many of the same causes: unstable power, weak grounding, or poor cabling. Let’s look at what triggers each type and how to fix them for clear, stable video on your DVR system.
4 Causes of Horizontal Lines on Security Camera Feed
1. Unstable Power Supply
Analog cameras need a constant 12 V DC feed. When the power adapter or shared power board can’t maintain steady voltage—especially when IR LEDs activate at night—horizontal bars or “hum lines” appear.
- Fix: Use a regulated power adapter rated at least 2 A per camera, or upgrade to a certified CCTV power distribution box.
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2. Ground Loop Interference
If your DVR and cameras are plugged into different outlets, a small voltage difference between grounds can create noise across the analog video signal.
- Fix: Power all equipment from one outlet or surge-protected strip. If needed, install a ground-loop isolator on the BNC video line.
3. Voltage Drop at Night
When IR LEDs switch on, the camera draws more current. Long or thin power cables can cause voltage to drop below 11.5 V, introducing rolling horizontal bars.
- Fix: Shorten power cable runs, use heavier-gauge cable, or provide a dedicated 12 V 2 A supply per camera.
4. Poor Shared Power Boards
Multi-output boards without proper filtering often leak electrical ripple between channels. As all cameras draw current, the noise spreads across the system.
- Fix: Replace low-quality boards with UL-listed, regulated CCTV power units or test each camera on its own power adapter.
4 Causes of Vertical Lines on Security Camera
1. Cable Shielding or Interference
Vertical lines on security camera often indicate signal distortion from unshielded or damaged coaxial cables. Nearby 110 V wiring, motors, or fluorescent lights can introduce electromagnetic noise.
- Fix: Keep coax or balun cables separated from power lines and replace any cable with visible damage.
2. Loose or Corroded BNC Connectors
A weak BNC connection between the camera and DVR disrupts video sync, producing vertical stripes or flicker.
- Fix: Reseat or replace connectors, ensuring they fit tightly with clean contacts.
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3. Signal Timing or Sync Issues
Long cable runs or mismatched impedance from cheap baluns can distort horizontal sync pulses, causing vertical flicker or banding.
- Fix: Use 75-ohm RG59/RG6 coax cable or high-quality passive baluns rated for your camera distance.
4. Sensor or Board Faults
If only one camera shows vertical lines regardless of power or cable swaps, its internal CCD/CMOS board may be failing.
Fix: Replace the faulty camera module or upgrade to a modern HD-BNC model.
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Quick Troubleshooting Steps
- Compare feeds in day vs. night mode to see when the lines appear.
- Test one camera on a separate power adapter.
- Measure voltage at the camera with IR on; ensure it stays near 12 V DC.
- Keep video cables away from power wiring and confirm all BNC connections are firm.
- Plug DVR and cameras into the same outlet to avoid ground-loop hum.
FAQs About Horizontal and Vertical Lines on Security Camera Feed
How to fix horizontal lines on camera?
Use a regulated 12 V power supply, share one power circuit for all equipment, and check cable shielding. If the issue appears only at night, IR current draw is causing voltage drop.
What causes lines in security cameras?
Lines come from power ripple, grounding differences, or signal interference. Weak adapters, long cable runs, or cheap splitters are the usual culprits.
Why are there horizontal lines on my camera screen?
The analog security camera’s power source is unstable or overloaded. At night, IR LEDs increase power demand, exposing noise in the video signal.
Why does my video have horizontal or vertical lines?
Analog signals pick up electrical noise from poor cables or inconsistent voltage. Use shielded coax, stable power, and good grounding to remove interference.
Keep Your Security Camera Feed Free from Lines
Most analog video interference is easy to fix with stable power and quality cabling. If you still see lines after testing, contact Camius for help choosing:
- Regulated 12 V DC power supplies
- Shielded coax or HD-BNC cables
- Ground-loop isolators
- Replacement analog cameras
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