Having a dark shadow on your LG TV screen can be annoying and make it difficult to enjoy watching shows and movies. This issue is often caused by something blocking or interfering with the TV’s backlight system. With some investigation and troubleshooting, you can likely resolve the problem independently without needing to call in TV repair experts.
What Causes a Dark Shadow on an LG TV Screen?
There are a few common culprits for dark shadows on LG TVs:
Faulty or Failing LED Backlights
Modern LG TVs use LED (light emitting diode) backlight systems to illuminate the LCD display panel. If some of these LEDs start to fail and burn out, it can cause darker patches on the screen.
Objects Blocking the Backlights
If you place any items too close to the back of the TV, they can physically block light from parts of the backlight system and cast shadows. This could include things like cables, game consoles, DVD players, etc.
Sometimes, the LED backlights across the screen provide uneven illumination, resulting in darker areas on parts of the display.
Damaged LCD Panel
Though less common, cracks or impacts to the LCD panel itself can block light transmission and cause shadows or dark patches.
Fixing Steps of Dark Shadow on LG TV Screen
In this guide, I’ll walk you through the major causes of dark shadows on LG TVs and the steps you can take to fix them.
Inspecting the Back of the TV
Before doing anything too involved, inspect the back of the LG TV for any obvious issues. Look for these two problems:
1. Objects Blocking Backlights
Carefully examine the rear of the TV, looking for any items that could be blocking light from the backlights. Ensure no cables, media players, power cords, or other objects are touching or pressed against the back panel. Move anything away from the rear of the TV.
2. Damaged Backlights
Check for any signs of damage, burned-out areas, or cracked backlight panels. You may see discolored or darker patches on the backlights corresponding to the location of shadows on the TV screen. If the backlights appear damaged, they will likely need professional service.
If neither of these seems to be the cause, move on to troubleshooting the other potential issues.
Checking for Backlight Issues
If the back of the TV appears normal, the next thing to check for is problems with the LED backlight system itself. Try these checks:
1. LED Backlight Test
Access the built-in LG diagnostics menu and activate the “LED backlight” test. This will allow each section of the backlight to light up independently. Compare the brightness across different areas to check for settings.
Reset any custom backlight settings or modes. Choose a preset picture mode like “Standard” or “Vivid” to return the backlight settings to default.
3. Update TV Firmware
Check online for any firmware updates for your specific LG TV model and install the latest software update. Updates sometimes resolve backlight issues.
4. Local Dimming Issues
If your LG TV has local dimming zones, you may need to adjust settings or turn this feature off entirely if it’s not functioning correctly and causing shadows.
These tests will help determine if the LED backlight system is malfunctioning and requires repair.
Checking for Panel Damage
Though less likely, screen panel damage can also let light leak out and cast shadows on the display. Here’s how to check for panel issues:
1. Examine the Panel
Closely inspect the surface of the LCD panel for any cracks, chips, or visibly damaged areas. Use a bright flashlight at an angle to illuminate any defects.
2. Apply Pressure
Gently apply pressure with your fingers around the perimeter of the dark shadow area. If you see the shadow change or lessen when pressure is applied, it indicates a panel issue.
3. Display Test Patterns
Use LG diagnostics to display test patterns like solid colors or black/white screens. This can make panel damage more apparent if certain colors and patterns worsen the issue.
4. Check Impact Marks
Carefully examine the panel frame and edges for any impact marks or physical damage. Cracks often stem from impact points.
Panel repairs or replacements are beyond DIY fixes and will require professional TV repair if damage is found. But this can at least help diagnose panel issues as the cause.
Adjusting Display Settings to Improve Uniformity
For mild backlight unevenness causing shadows, you can often compensate by adjusting display settings:
1. Turn up the Backlight/OLED Light
Increasing overall backlight brightness can help minimize the appearance of shadows. Just take care not to overdrive the backlights.
2. Adjust Local Dimming
Expanding local dimming zones can help even out the backlight blooming that sometimes causes shadows.
3. Enable Uniformity Correction
LG TVs have uniformity correction features that can compensate for uneven backlighting. Enabling this may reduce backlight shadows.
4. Calibrate to a Darker Room
Reducing ambient room light helps mask mild backlight uniformity issues that cause shadows.
5. Try a Darker Preset Picture Mode
Using a picture preset like “Cinema” or “ISF Dark Room” lowers backlight intensity for a more uniform image.
6. Update TV Firmware
Install the latest firmware, which sometimes improves display algorithms and backlight uniformity.
These adjustments won’t fix severe backlight issues but can help improve the appearance of dark shadows on the screen.
When to Call for TV Repair Service
If you still see pronounced dark shadows on the TV screen after troubleshooting, it likely indicates an LED backlight failure or physical damage that requires professional repair:
- Several burnt-out or cracked LEDs – Several dead LEDs in the backlight system must be repaired and replaced.
- Backlights not fully lighting – If sections of the backlight system don’t light up during LED tests, a new backlight may be needed.
- Visible panel damage – Cracks, chips, or impact points on the LCD panel itself require panel replacement to fix shadows.
- Shadows worsening over time – If the dark areas progressively get larger, it indicates failing backlights.
- Shadows unaffected by adjustments – Professional service may be needed if display settings don’t improve the shadow appearance.
- Under manufacturer’s warranty – Your LG TV may still be under the 1-year manufacturer’s warranty, which would cover repairing backlight issues.
While a dark shadow on your LG TV may seem daunting, a bit of diligent troubleshooting can often uncover the cause. Adjusting display settings or removing objects blocking the backlights might provide an easy fix. But for severe shadows or backlight failure, TV repair technicians have the proper tools and parts to accurately diagnose problems and get your LG TV looking as good as new.