LG OLED TV Error F31 – Quick Fix Guide

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What This Error Means

F31 on an LG OLED TV is a panel/main board communication fault.

Translated: the main board and the OLED panel are not talking properly, so the TV boots weird, shows no picture, glitches, or shuts itself down while throwing F31.

LG doesn’t publish this neatly for every model, but on chassis that use F-codes, F31 usually means the control electronics can’t reliably drive the panel. Could be a bad board, bad connector, or occasionally a software/firmware mess.

Official Fix

Here’s the “by the book” path LG (or the manual) expects:

  • 1. Full power kill.
    Unplug the TV from the wall. Not just standby. Pull the plug for at least 5–10 minutes so the boards fully discharge.
  • 2. Strip all accessories.
    Disconnect every HDMI device, soundbar, USB stick, antenna, game console, etc. You want the TV alone, straight into the wall outlet (no surge strip, no UPS).
  • 3. Reboot clean.
    Plug back in. Turn the TV on with the remote. If F31 was a one-off glitch, it sometimes clears here.
  • 4. Run built-in self-check.
    Go to: Settings → All Settings → Support → OLED Care / Device Self Care → Self Diagnosis (names vary a bit). Run picture test and hardware check. If it flags panel or main board, that lines up with F31.
  • 5. Update firmware.
    Still working enough to show menus? Then: Settings → All Settings → Support → Software Update. Turn on Auto Update and hit Check for Updates. Install anything pending, then power the TV off and back on.
  • 6. Factory reset (if the picture still works sometimes).
    Menu path is usually: Settings → All Settings → General → System → Reset to Initial Settings. This wipes apps and settings; it will not fix a burned board, but can clear software corruption that triggers panel faults.
  • 7. Call LG / authorized service.
    If F31 stays, the official next step is paid service. LG’s script is usually: diagnose, then swap the main board, and if that fails, replace the panel assembly or related driver board. No board-level repair, just full module swaps.

If you’re under warranty, stop here and let LG own it. Don’t open the set or you hand them an excuse to walk away.

The Technician’s Trick

This is what people who actually fix these try before ordering a new panel. Do this at your own risk. High voltages live inside even when it looks dead.

  • 1. Real power drain, not the fake “reboot”.
    • Unplug the TV from the wall.
    • With it unplugged, press and hold the TV’s physical power button (on the set, not the remote) for 20–30 seconds.
    • Let it sit another 2–3 minutes, then plug back in and power on.
    • This hard-resets some protection circuits and clears half-latched panel drivers that a normal reboot doesn’t touch.
  • 2. Kill HDMI-CEC nonsense.
    • Reconnect just one HDMI source (ideally nothing fancy, like a basic streaming stick).
    • Go to: Settings → All Settings → General → Devices → HDMI Settings and turn SIMPLINK (HDMI-CEC) off.
    • Reboot the TV again. Sometimes a bad HDMI device or CEC loop can push the set into protection that then reads as a fault code.
  • 3. USB firmware reload (when the menus are half-working).
    • On a computer, grab the latest firmware for your exact model from LG’s support site.
    • Put the file on a USB drive exactly how LG says (usually in an LG_DTV folder).
    • Plug the USB into the TV, power it on, and let it offer the update. Don’t touch anything until it’s done.
    • If F31 is coming from corrupted firmware or a botched update, this sometimes brings the panel back to life.
  • 4. Reseat the panel cable (only if you’re comfortable opening it).
    • Warning: Unplug from the wall, wait at least 10 minutes. If you don’t know what you’re looking at inside a TV, stop here.
    • Remove the back cover carefully. The OLED panel is thin and fragile. Don’t flex it.
    • Find the wide ribbon or ribbons running from the main board to the panel / T-Con area.
    • Pop the locking tabs, gently pull the ribbon, inspect for burns or kinks, then push it back in fully and lock it down.
    • Do the same for any other obvious panel-related ribbon connectors you can reach without forcing anything.
    • Reassemble, plug in, and test. A half-seated ribbon is a classic, stupid reason for F-type panel faults.
  • 5. Visual sniff test before you buy parts.
    • With the back off, look closely at the main board and power board.
    • Check for burned spots, cracked chips, or obviously blown components around the panel output area.
    • If you see scorch marks near the panel connectors, odds are high the panel or driver side is toast; don’t waste money shotgun-replacing random boards.

If reseating and power-draining don’t change anything and F31 is solid, you’re likely looking at a main board or panel-level failure, no easy magic.

Is It Worth Fixing? (The Financial Verdict)

  • ✅ Fix: Under warranty, extended warranty, or out-of-warranty repair quote is under ~40% of a similar new OLED and it’s just a main board swap.
  • ⚠️ Debatable: TV is a large, higher-end OLED (65″+), 3–6 years old, and the shop says it might be main board but panel could also be bad; only proceed if you’re okay gambling on used/refurb parts.
  • ❌ Replace: Panel or panel-driver is confirmed bad, or total repair cost is over ~60–70% of a new comparable OLED; in that case, your money is better in a new set.

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