Why Are There Vertical Lines, Flickering or Ghosting on Your Tv Screen?

Television Repair in Nairobi, Kenya >0704843613

Fast fixes for the most common display problems — with detailed repair steps below.


 Summary

ProblemMost Likely CauseQuick Fix
Vertical linesLoose/damaged display cableReseat or replace the cable
Screen flickeringFaulty refresh rate or driverUpdate GPU drivers & adjust refresh rate
GhostingSlow pixel response timeEnable overdrive in monitor settings
All of the aboveHardware failureContact a technician

📞 Need professional help? Call or WhatsApp: 0704843613

 

1. What Causes Vertical Lines on a Screen?

Vertical lines running down your screen are one of the most reported display issues. They appear as thin or thick coloured or black lines and can be caused by:

  • Loose or damaged display cable (most common on laptops)
  • Damaged LCD/OLED panel
  • Faulty graphics card (GPU)
  • Overheating of the display hardware
  • Physical impact or pressure on the screen

Quick Fix for Vertical Lines

  1. Restart your device — rules out a temporary software glitch.
  2. Connect an external monitor — if lines don’t appear on the external display, the fault is in your screen, not the GPU.
  3. Gently press around the screen bezel — if lines shift or disappear, a loose internal cable is the culprit.

2. What Causes Screen Flickering?

Screen flickering is characterised by a rapid, unstable flashing of the display. Common causes include:

  • Incompatible or outdated graphics drivers
  • Incorrect refresh rate settings
  • Loose video cable connection
  • Failing backlight (especially on older LCD screens)
  • Incompatible applications conflicting with the display adapter

Quick Fix for Screen Flickering

  1. Update your graphics drivers via Device Manager (Windows) or System Preferences (Mac).
  2. Check your refresh rate — set it to the manufacturer’s recommended rate (commonly 60Hz or 144Hz).
  3. Boot in Safe Mode — if flickering stops, a software or driver conflict is the cause.

3. What Causes Screen Ghosting?

Screen ghosting appears as a trail or “shadow” left behind moving objects on your display. It is most noticeable during gaming or video playback. Causes include:

  • Slow pixel response time (common on cheaper IPS monitors)
  • Overdrive setting set too low or too high
  • Low refresh rate monitor being pushed beyond its capability
  • Signal interference from cables

Quick Fix for Screen Ghosting

  1. Enable or adjust Overdrive in your monitor’s on-screen display (OSD) menu.
  2. Reduce your screen resolution temporarily to see if ghosting reduces.
  3. Replace the display cable — HDMI or DisplayPort cables can cause ghosting if damaged.

4. How to Diagnose Your Display Problem

Before attempting any fix, follow these diagnostic steps to identify whether the problem is hardware or software.

Step-by-Step Diagnosis

Step 1: Connect to an External Monitor Plug your device into an external screen using HDMI or VGA. If the problem disappears on the external display, the issue is with your laptop screen or its cable — not the GPU.

Step 2: Check for Physical Damage Inspect your screen for cracks, pressure marks, or liquid damage. Physical damage typically requires screen replacement.

Step 3: Restart in Safe Mode

  • Windows: Press F8 during startup → select Safe Mode
  • Mac: Hold Shift during startup

If the issue disappears in Safe Mode, a third-party app or driver is causing the problem.

Step 4: Run a Monitor Test Use free tools like Dead Pixel Test or PassMark MonitorTest to run a full-screen colour test and identify exactly where the fault lies.

Step 5: Check Device Manager (Windows) Open Device Manager → Display Adapters → look for any warning icons (yellow triangles). These indicate driver or hardware faults.


5. Detailed Fix: Vertical Lines on Screen

Fix 1 — Update or Roll Back Graphics Drivers

  1. Right-click the Start Menu → select Device Manager
  2. Expand Display Adapters
  3. Right-click your GPU → select Update Driver
  4. If lines appeared after a recent update, select Roll Back Driver instead
  5. Restart your device and check if the issue is resolved

Fix 2 — Reseat the Display Cable (Laptops)

⚠️ This requires opening the laptop. If you are not confident, seek a professional technician.

  1. Power off the laptop completely and remove the battery
  2. Remove the screen bezel (the plastic border around the screen) using a plastic pry tool
  3. Locate the display cable connecting the screen to the motherboard
  4. Carefully disconnect and reconnect the cable, ensuring it clicks firmly into place
  5. Reassemble and power on to test

Fix 3 — Replace the LCD/LED Panel

If the cable is intact and the issue persists, the screen panel itself may be damaged. Contact a repair technician for a screen replacement.


6. Detailed Fix: Screen Flickering

Fix 1 — Adjust the Refresh Rate

Windows:

  1. Right-click the desktop → Display Settings
  2. Scroll down → click Advanced Display Settings
  3. Under Refresh Rate, select the recommended or highest available option
  4. Click Keep Changes

Mac:

  1. Go to Apple Menu → System Settings → Displays
  2. Select the correct refresh rate for your monitor

Fix 2 — Reinstall Graphics Drivers

  1. Download DDU (Display Driver Uninstaller) — a free tool
  2. Boot into Safe Mode
  3. Run DDU and select Clean and Restart
  4. After restart, download and install the latest driver from the manufacturer’s website (NVIDIA, AMD, or Intel)

Fix 3 — Check for App Conflicts

  1. Open Task Manager (Ctrl + Shift + Esc)
  2. Check whether flickering occurs only when a specific app is open
  3. If yes, update or uninstall that application
  4. Common culprits include antivirus software and older productivity tools

Fix 4 — Replace the Backlight

If none of the above work and the flickering has a faint brightness variation (not just pixel-level), the backlight inverter may be failing. This is a hardware issue requiring professional repair.


7. Detailed Fix: Screen Ghosting

Fix 1 — Enable Overdrive on Your Monitor

  1. Press the Menu button on your monitor (usually on the side or bottom bezel)
  2. Navigate to Picture Quality or Response Time settings
  3. Enable Overdrive — start at Medium and adjust based on results
  4. Avoid setting Overdrive too high as it can cause inverse ghosting

Fix 2 — Replace the Display Cable

  1. Power off your monitor and PC
  2. Disconnect the current HDMI, DisplayPort, or DVI cable
  3. Replace with a high-quality certified cable (preferably DisplayPort for gaming monitors)
  4. Power back on and test

Fix 3 — Upgrade Your Monitor

If your monitor has a refresh rate below 75Hz and you are gaming or watching fast-paced video, ghosting may be an inherent limitation of the display. Consider upgrading to a 144Hz IPS or OLED monitor for a ghost-free experience.


8. When to Replace vs Repair Your Screen

SituationRecommended Action
Cracked or shattered screenReplace the screen
Vertical lines without physical damageRepair — likely cable or driver issue
Flickering after driver updateRepair — software fix
Ghosting on a budget monitorUpgrade the monitor
Flickering with dim screenRepair — backlight replacement
Lines on multiple outputs (screen + HDMI)GPU replacement required

9. Get Professional Help

If you have tried the steps above and your screen still shows vertical lines, flickering, or ghosting, it is time to consult a certified technician. Attempting advanced hardware repairs without the right tools can cause further damage.


 Contact Us Today

Call or WhatsApp: 0704843613

We diagnose and repair all types of screen issues including:

  •  Laptop and desktop screen replacement
  •  GPU and graphics card faults
  •  Monitor cable and connector repairs
  •  Backlight and inverter replacement
  •  Driver and software-related display issues

Fast, affordable, and professional screen repair — get in touch today.


Last updated: May 2026 | Screen repair & display troubleshooting guide