F-3 Button/key error on touchpad

minor

The Lg F-3 error code on your microwave indicates: Button/key error on touchpad. This typically requires troubleshooting the button ui system.

LG Microwave Affects 2 models

What Causes Error F-3

high likelihood #1

Stuck or shorted key on the control panel

A button is physically stuck, or moisture has caused a short across the membrane switch.

high likelihood #2

Control panel membrane failure

The flexible membrane layer with the touch-sensitive buttons has worn through or cracked.

medium likelihood #3

Display board failure

The UI/display board that reads button presses has failed.

low likelihood #4

Ribbon cable issue

The flat cable connecting the panel to the control board is damaged or loose.

How to Fix Error F-3

  1. Step 1: Power cycle the appliance

    Unplug for 5 minutes. Button errors often clear when the capacitive touch system resets.

  2. Step 2: Clean the control panel

    Wipe the entire panel with a soft damp cloth. Dried spills, grease, or food residue can trigger false button presses. Do not spray cleaner directly on the panel — spray the cloth.

  3. Step 3: Check for stuck buttons

    Press every button on the panel one by one. Feel for any that don't spring back or feel different from the others. A stuck button will continuously trigger the error.

  4. Step 4: Disconnect and reseat the ribbon cable

    Unplug the appliance. Remove the panel cover/screws and carefully reseat the ribbon cable connecting the control panel to the board.

    ⚠️ Ribbon cables are delicate — don't force them.

  5. Step 5: Replace the control panel overlay

    If the membrane touchpad is worn, blistered, or cracked, order a replacement overlay. It typically peels off and the new one sticks on.

Parts You Might Need

If troubleshooting doesn't resolve error F-3, you may need to replace one of these parts:

Control Panel/Touchpad

other $40-$120
Find on Amazon PartSelect

Display Board

board $50-$150
Find on Amazon PartSelect

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When to Call a Professional

If the control panel replacement doesn't fix the issue, suggesting the electronic board behind it has failed

  • Display boards can be expensive ($100+) and worth confirming before ordering
  • Some touchpad panels are integrated with the door and hard to replace
  • Intermittent button errors may indicate water intrusion requiring disassembly to dry

Video Repair Guides

Watch a repair walkthrough for this error code on YouTube:

▶ Search YouTube for "LG microwave error F-3 fix"

Models Affected

This error code has been reported on the following LG microwave models:

LMV2031STLMVH1711ST