LG OLED TV F35 Error Code Guide (Real-World Fixes)

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What This Error Means

F35 on an LG OLED TV is an internal fault / protection code. The TV thinks something is wrong in its power or control electronics and locks itself down.

In plain terms: the main board and power supply aren’t talking properly to the OLED panel, so the set reboots, stays dark, or throws F35 instead of showing a picture.

  • Not a wrong-input problem.
  • Not a bad HDMI cable issue.
  • Usually a power, firmware, or main-board fault.

If it comes back right after you power it up, the TV is failing its self-check when it tries to drive the panel.

Official Fix

LG treats F35 as a service-level error. Their playbook is simple: basic reset, then call a tech.

  • 1. Hard power reset (LG-approved version)
    • Turn the TV off.
    • Unplug the power cord from the wall.
    • Leave it unplugged for at least 60 seconds.
    • Plug it straight into a wall outlet (no strip, no surge bar) and try powering on again.
  • 2. Strip it down to just the TV
    • Unplug all HDMI devices (consoles, soundbars, streaming sticks, PC).
    • Unplug USB drives and any external storage.
    • Try powering on with only the power cord connected.
    • If F35 disappears with everything disconnected, one of those devices or cables may be tripping protection.
  • 3. Check the obvious power stuff
    • Make sure the wall outlet is solid: test it with a lamp.
    • If you were using a cheap power strip, stay off it. Go direct to the wall.
    • Check the TV’s power cord is fully seated in the back of the set.
  • 4. Try a software update (only if it boots enough)
    • If you can reach the menu at all, go to: Settings > All Settings > Support > Software Update.
    • Run Check for Updates and install anything it finds.
    • After the update, let the TV reboot on its own. Don’t yank the plug mid-update.
  • 5. When the manual says “Stop. Call LG.”
    • If F35 keeps coming back after the reset and update, LG’s official answer is service only.
    • Contact LG support with your model, serial number, and the F35 code.
    • Authorized service will usually:
      • Run internal diagnostics with a service remote.
      • Check power supply voltages and protection lines.
      • Replace the main (logic) board if it’s a control/firmware fault.
      • Replace the power supply board if voltages are unstable.
      • In rare cases, replace the OLED panel assembly if the panel itself is faulting.

The official stance: no user-serviceable parts inside for F35. If a basic reset and update don’t clear it, they want a tech on it.

The Technician’s Trick

Here’s what bench techs usually try before ordering expensive boards. Do this only if you’re comfortable with basic troubleshooting.

  • 1. Real “power drain” reset
    • Turn the TV off and unplug it from the wall.
    • On the TV itself (not the remote), press and hold the power button for 30 seconds.
    • Let it sit another 5 minutes unplugged.
    • Plug back in and power on.
    • This bleeds off the power supply and can clear a latched protection state that a quick unplug won’t touch.
  • 2. Full factory reset from the menus (if you can get any picture at all)
    • With the TV on, hit Settings on the remote.
    • Go to All Settings > General > Reset to Initial Settings.
    • Confirm the reset and let the TV reboot and walk through setup again.
    • Corrupted settings/NVRAM can trigger protection codes; a full reset wipes that out.
  • 3. USB firmware reload (more advanced, but still DIY)
    • On a PC, go to LG’s support page for your exact TV model.
    • Download the latest firmware and follow LG’s instructions to put it on a FAT32 USB stick.
    • With the TV off, plug the USB into the TV.
    • Power the TV on and wait. Many models will auto-detect the firmware and prompt to update.
    • Let the process finish. Do not cut power during this.
    • If F35 was caused by a corrupted firmware image, this can bring it back.
  • 4. Out-of-warranty only: quick connector check
    • Warning: You can get shocked off the power board if you’re careless. If you’re not handy with tools, skip this.
    • Unplug the TV and leave it for at least 10–15 minutes to let capacitors discharge.
    • Carefully remove the back cover (keep track of screws).
    • Gently press on the multi-pin plugs going between the power board, main board, and panel driver boards to make sure they’re seated.
    • Do not yank on ribbon cables; just make sure nothing is obviously loose or half-plugged.
    • Reassemble, power up, and see if F35 is gone.

If none of that even changes the behavior, you’re likely looking at a bad main board, power board, or panel — no magic combo of buttons will fix that.

Is It Worth Fixing? (The Financial Verdict)

  • ✅ Fix: TV is under warranty, or it’s a 55″+ premium OLED less than ~5 years old and the quote to replace a board is clearly cheaper than a new set.
  • ⚠️ Debatable: Mid-range OLED that’s 5–7 years old, out of warranty, with a repair quote in the few-hundred-dollar range and no major burn-in yet.
  • ❌ Replace: Panel has visible burn-in, cracks, or lines plus an F35 fault, or the repair quote is over ~60–70% of the cost of a new comparable TV.

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