LG Microwave F-7 — Inverter / power module fault (NeoChef inverter models)
LG Microwave · Error code F-7
What F-7 Means
On LG NeoChef and other inverter microwaves, F-7 indicates the inverter power module has reported a fault — overcurrent, overheat, or self-test failure. The microwave will not heat.
Symptoms
- F-7 on display on a NeoChef / inverter model
- No heat even though fan and turntable run
- Audible click then shutdown shortly after start
- Inverter fan may run faster than normal
Common Causes
The Smart Inverter module has failed — the most common cause on this code.
A shorted magnetron pulls excessive current and trips the inverter's self-protect.
Lint or grease on the inverter heatsink causing thermal shutdown.
Connector to the magnetron or main board has loosened.
How to Fix It
- Unplug for 5 minutes and retest with a cup of water — confirm no heat output before disassembly.
- Vacuum the rear vent grilles and check that the cooling fan spins freely.
- ONLY trained technicians should open the chassis — inverter capacitors hold dangerous charge.
- Inspect the inverter board for burn marks, bulged caps, or burnt connectors.
- Reseat the inverter-to-magnetron and inverter-to-main-board harnesses.
- Test the magnetron filament; if shorted, replace it before replacing the inverter.
- Replace the inverter (Smart Inverter) module if visibly damaged or if the magnetron tests good.
- Run a 1-minute water test; if F-7 returns, escalate.
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.
More LG 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.