My LG TV Had Horizontal Lines – Here’s How I Fixed It Without Paying $320

Last month, I settled in to watch the playoffs on my LG C2 OLED, only to find three thin horizontal lines cutting across the screen like digital scars. At first, I thought it was the broadcast – until I switched inputs and the lines followed. That sinking feeling when you realize your TV might be dying? Yeah, I had that.

But before you start shopping for replacements or scheduling a repair appointment, there’s actually a lot you can try yourself. I spent the better part of a weekend diagnosing my issue, and along the way, I discovered that horizontal lines on LG TVs have multiple causes; some surprisingly simple to fix, others requiring professional intervention.

Here’s everything I learned about fixing horizontal lines on LG TVs, organized from the easiest fixes to the more involved solutions.

Understanding What Causes Horizontal Lines

Horizontal lines on your LG TV can stem from several sources:

• Loose or damaged cable connections causing signal interference
• HDMI handshake issues between source devices and the TV
• Software glitches in the TV’s firmware
• T-Con board failures (Timing Control board that processes video signals)
• Panel damage from physical impact or manufacturing defects
• External interference from nearby electronic devices
• Power supply issues causing insufficient voltage to display components

The key is methodically eliminating causes from simplest to most complex.

Step 1: Check Your Cable Connections

I started here because it’s the easiest fix – and it actually solved my problem temporarily.

What to do:

1. Turn off your TV and unplug it from power
2. Disconnect all HDMI cables, component cables, and any other video inputs
3. Inspect each cable for visible damage, bent pins, or corrosion
4. Firmly reconnect each cable, ensuring you hear/feel the click
5. If you have spare HDMI cables, swap them out to test
6. Try different HDMI ports on your TV

Why this works: Loose connections can cause intermittent signal disruption that manifests as horizontal lines. HDMI cables are particularly sensitive to partial disconnections.

In my case, re-seating the HDMI cable from my streaming device eliminated the lines for about two days, then they came back, pointing to a deeper issue.

Step 2: Test with Different Input Sources

This helps determine whether the problem is your TV or your source devices.

What to do:

1. Disconnect all external devices
2. Check if lines appear on the TV’s home screen or built-in apps
3. Connect a different device (DVD player, laptop, game console)
4. Try the TV’s internal apps (Netflix, YouTube, etc.)

What the results mean:

• Lines only with specific devices: The problem is your source device or cable, not the TV
• Lines on all inputs including smart TV apps: The issue is internal to the TV
• Lines that move or flicker: Often software or T-Con board related
• Static lines in fixed positions: More likely panel damage

When I tested mine, the lines appeared across all inputs and even on the home screen menu. That told me this was definitely a TV hardware issue, not my streaming box.

Step 3: Power Cycle Your LG TV Properly

A proper power cycle can reset hardware components and clear temporary glitches.

What to do:

1. Turn off the TV using the remote
2. Unplug the TV from the wall outlet (not just the power strip)
3. Press and hold the power button on the TV itself for 30 seconds
4. Leave unplugged for at least 5 minutes (I left mine for 20)
5. Plug back in and power on

Why this works: This fully discharges capacitors in the TV’s power supply and resets microcontrollers. It’s more effective than just turning the TV off and on.

This didn’t fix my lines, but I’ve seen it work for others with intermittent line issues.

Step 4: Update Your TV’s Firmware

Software bugs can occasionally cause display artifacts including horizontal lines.

What to do:

1. Press the Settings button on your LG remote (gear icon)
2. Navigate to “All Settings” → “General” → “About This TV”
3. Select “Check for Updates”
4. If an update is available, download and install it
5. Allow the TV to restart completely

Alternative method if TV is unusable:

1. Go to LG’s support website on your computer
2. Search for your TV model number
3. Download the latest firmware to a USB drive
4. Insert USB into TV and follow on-screen prompts

My TV was already on the latest firmware, so this didn’t help—but it’s worth checking since LG has fixed display issues through software updates before.

Step 5: Adjust Picture Settings and Disable Features

Some picture processing features can cause line artifacts, especially when combined with certain content types.

What to do:

1. Go to Settings → Picture → Picture Mode Settings
2. Try switching to “Standard” mode (disable Cinema, Vivid, Game modes)
3. Turn off “TruMotion” (motion smoothing)
4. Disable “Black Frame Insertion” if available
5. Turn off “Dynamic Contrast”
6. Set “Sharpness” to 0 or 10
7. Disable any AI picture processing features

Also try:

• Switching from HDR to SDR mode
• Changing screen resolution on connected devices
• Disabling HDMI Deep Color for each port

I disabled TruMotion and all AI processing, which made the lines slightly less noticeable but didn’t eliminate them.

Step 6: Check for External Interference

Electronic devices can sometimes cause display interference.

What to do:

1. Temporarily unplug nearby devices: soundbars, wireless routers, baby monitors, USB hubs
2. Move your TV away from speakers or other electronics
3. Try a different power outlet, preferably on a different circuit
4. Remove any USB devices plugged into the TV
5. Disconnect ethernet cable and use Wi-Fi only (or vice versa)

This is unlikely to be your issue if the lines are perfectly straight and stationary, but it’s worth ruling out.

Step 7: Factory Reset Your LG TV

A factory reset wipes all settings and can resolve persistent software issues.

What to do:

1. Go to Settings → General → System → Reset to Initial Settings
2. Confirm the reset (this will erase all settings and installed apps)
3. Follow the initial setup wizard after restart
4. Test before reinstalling apps or changing settings

Important: Write down your picture settings and Wi-Fi password first—you’ll need to reconfigure everything.

In my case, the factory reset didn’t change anything. The lines persisted exactly as before, confirming this was a hardware failure.

Step 8: Test with TV Back Panel Removed (Advanced)

Warning: This involves opening your TV and can void your warranty. Only attempt if you’re comfortable with electronics.

What to do:

1. Unplug TV and wait 30 minutes
2. Remove back panel screws (usually around the perimeter)
3. Carefully remove the back panel
4. Locate ribbon cables connecting the T-Con board to the panel
5. Gently reseat each ribbon cable
6. Check for any obvious damage, burn marks, or bulging capacitors
7. Reassemble and test

What to look for:

• Loose ribbon cable connections can cause line issues
• The T-Con board is usually a small circuit board near the top or side
• Look for part numbers—you may be able to order a replacement T-Con board for $30-80

I found one ribbon cable that wasn’t fully seated. After reconnecting it properly, the lines disappeared for about a week—then gradually returned. This pointed to either a failing T-Con board or panel damage.

Step 9: Professional Diagnosis – T-Con Board vs Panel

At this point, you’re looking at either replacing the T-Con board or accepting that the panel itself is damaged.

T-Con board replacement:

• Cost: $50-150 for the part, $100-200 for labor
• Difficulty: Moderate DIY project if you’re handy
• Success rate: High if T-Con is the actual problem

Panel replacement:

• Cost: Usually 60-80% of a new TV’s price
• Difficulty: Not practical for DIY
• Recommendation: Usually better to buy a new TV

How to decide:

If your lines are:

• Thin, flickering, or change with content: More likely T-Con board
• Thick, static, or in specific locations: More likely panel damage
• Appear gradually over time: Could be either
• Appeared after physical impact: Almost certainly panel damage

I called LG support and sent them photos. They confirmed it was likely a T-Con board failure given the thin, consistent nature of the lines. However, my TV was out of warranty, and the repair quote was $320—more than I wanted to spend on a 3-year-old TV.

Step 10: Check Warranty and Consider Repair Options

Before spending money, verify your coverage.

Check these:

1. LG manufacturer warranty – Usually 1 year for parts/labor on panels
2. Extended warranty – If you purchased through retailers like Best Buy
3. Credit card protection – Some cards extend manufacturer warranties
4. Retailer return policy – If TV is recently purchased

Get multiple quotes:

• LG authorized service centers
• Independent TV repair shops
• DIY T-Con board replacement from eBay or Amazon

Repair cost reality check:

• If repair costs more than 40% of a replacement TV, just replace it
• OLED panels are especially expensive to repair
• Labor costs vary widely by region ($75-200 per hour)

What I Ended Up Doing

After weighing my options, I decided to attempt a DIY T-Con board replacement. I ordered the board for $65 on eBay using my TV’s exact model number, watched several YouTube tutorials, and replaced it myself in about 45 minutes.

The lines completely disappeared, and my TV has been working perfectly for three months now. Total cost: $65 versus the $320 quote from LG’s service center.

However, I need to emphasize: this was a gamble. If the problem had been the panel instead of the T-Con board, I would have wasted $65 and still needed a new TV. I only attempted the repair because:

1. The TV was out of warranty anyway
2. The symptoms strongly suggested T-Con failure
3. I was prepared to buy a new TV if the repair failed
4. I’m comfortable working with electronics

When to Just Replace Your TV

Sometimes repair doesn’t make sense:

• TV is 5+ years old
• Repair costs exceed 40% of replacement cost
• Multiple previous repairs needed
• You’re seeing other issues beyond just lines
• The panel itself is damaged (vertical cracks, dark spots, dead pixels in same area as lines)

TV prices have dropped significantly in recent years. A comparable replacement to my LG C2 now costs less than what a panel replacement would have cost.

Prevention Tips for the Future

While horizontal lines can’t always be prevented, you can reduce the risk:

1. Use a surge protector – Protects against power fluctuations
2. Ensure proper ventilation – Don’t block vents on the TV back
3. Avoid static images – OLED burn-in can start with lines
4. Use quality HDMI cables – Cheap cables degrade faster
5. Keep firmware updated – LG releases bug fixes regularly
6. Gentle cleaning only – Never press hard on the screen
7. Stable mounting – Vibration can loosen internal connections

Final Thoughts

Horizontal lines on your LG TV are frustrating, but they’re not always a death sentence for your display. Start with the simple fixes—cable connections, power cycling, software updates—before assuming you need professional repair.

If you do end up needing hardware repair, get multiple quotes and seriously consider DIY if you’re comfortable with it. The T-Con board replacement was surprisingly straightforward, and the $255 I saved bought me a nice soundbar upgrade.

But also know when to walk away. If your TV is older or the repair quotes are astronomical, modern TVs offer significantly better value than they did even a few years ago.

The good news? You’re now equipped to diagnose the problem and make an informed decision about repair versus replacement.

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