Frigidaire · Microwave Serious
F7 — Inverter / magnetron drive fault
On inverter-equipped Frigidaire/Electrolux microwaves, F7 indicates the inverter board is reporting a fault driving the magnetron. The unit will refuse to heat.
- Keep using it?
- Limited use only
- DIY difficulty
- Hard
- Verified against
- frigidaire.com ↗
How to fix it
- DANGER: Inverter and HV section can store lethal energy — only proceed if trained.
- Unplug for 10 minutes and retry once to confirm hard fault.
- Verify cooling fan spins and vents are unobstructed.
- With power off and capacitors discharged, ohms-test magnetron filament (should read near zero) and filament-to-chassis (should read open).
- Replace magnetron if shorted to chassis.
- If magnetron checks good, replace the inverter board.
Why it happens
Typical signs: F7 on display · Microwave runs but does not heat · Buzzing or clicking from cabinet area · Burnt-electronics smell
- Failed inverter board Most common cause; inverter detects internal overcurrent.
- Shorted magnetron Magnetron filament or anode short pulls inverter into protection.
- Cooling fan failure causing overheat Inverter thermal protector tripped.
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 Frigidaire microwave 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: frigidaire.com.