LG · Oven Serious
F38 — Main-to-inverter communication error (induction models)
On LG slide-in induction ranges, the main control board has lost serial communication with the cooktop inverter board. Cooktop and sometimes oven function are blocked.
- Keep using it?
- Limited use only
- DIY difficulty
- Hard
- Verified against
- lgparts.com ↗
How to fix it
- Power off at the breaker for 60 seconds and retry.
- If F38 returns, disconnect power and remove the cooktop service panel to access the inverter board.
- Reseat the comm harness at both the inverter and the main board.
- Inspect for crushed pins, burned connectors, or melted insulation near the inverter heatsinks.
- Verify the chassis ground strap is intact between modules.
- Induction inverter and main-board service typically needs a tech — replace the inverter first, then the main board.
Why it happens
Typical signs: F38 or F-38 on display · Induction cooktop dead or all zones show error · Oven may still bake on some models · Code appears within seconds of power-on
- Loose comm harness between main board and inverter Plug worked loose during transport or service.
- Failed inverter board Cooktop inverter MCU not transmitting.
- Failed main control board Main PCB cannot receive on the bus.
- Damaged ground bond Floating ground between modules corrupts the comm signal.
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 oven codes
Always unplug an appliance before servicing it. This guide is for informational purposes and is not a substitute for a qualified technician. Verified against manufacturer documentation: lgparts.com.