F-A Serious Hard — consider a tech

LG Microwave F-A — Cooling fan / motor feedback error

LG Microwave · Error code F-A

What F-A Means

The control isn't getting the expected speed feedback from the cooling fan motor. Magnetron cooling is at risk, so the microwave shuts the cook cycle down.

Symptoms

  • F-A on display
  • Cook cycle aborts within seconds
  • Fan may sound slow, loud, or not run at all
  • Microwave may smell hot if it was running before fault

Common Causes

1
Failed / seized cooling fan motor

Bearings worn out from years of grease and heat.

2
Obstructed fan blade

Grease buildup or debris jamming the blade.

3
Loose fan motor harness

Speed feedback wire disconnected.

4
Main control board fault

PCB can't read the tach signal.

How to Fix It

  1. Unplug the microwave.
  2. Remove the cabinet and locate the magnetron cooling fan.
  3. Check that the fan blade spins freely by hand; clean off any grease.
  4. Reseat the fan motor connector at the board.
  5. Apply power briefly and listen for the fan; if it doesn't spin or runs slowly, replace the fan motor.
  6. If the fan runs correctly and harness is good but F-A persists, replace the main control board.

Parts You May Need

If diagnosis points to a failed part, these are the common replacements. As an Amazon Associate we earn from qualifying purchases.

Common replacement LG microwave cooling fan motor View on Amazon→ Common replacement LG microwave main control board View on Amazon→

More LG Microwave Codes

CH CH / Child Lock — Control locked DOOR DOOR / Door Error — Door switch / interlock fault EE EE — EEPROM / control memory error F-1 F-1 — Oven sensor open / thermistor fault F-2 F-2 — Keypad / touch panel shorted F-3 F-3 — Key short / specific button stuck

All LG codes → All microwave codes →

Verified against manufacturer documentation: lg.com

Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician.