What it means, first
This code says the microwave inverter and its wiring failed the check the control runs before it will produce microwave power. The oven side of a combination unit is usually unaffected: what is out is the microwave function, and it stays out until the power supply is repaired. A latched fault from a supply disturbance rather than a failed power supply is both the commonest cause and the cheapest to rule out, so it goes first.
This code, as the manufacturer publishes it
Reference| Code | Documented meaning |
|---|---|
| F4 E0 | There may be a problem with the microwave inverter, or the associated wiring. |
What an owner observes
- The code appears as soon as microwave power is called for — Immediate is the signature of a supply the control cannot prove.
- A buzz or a click and then the cycle ends — The control removing power it could not confirm.
- NEAR MISS - the display is dead and nothing runs — That is a supply or console fault and it is a different page.
What triggers this code, most likely first
- A latched fault after a supply disturbance — Ranked first because it is the only cause with a free cure: a full power-down clears a state the control cannot clear by itself.
- Microwave inverter itself — Second: this is a high-voltage assembly that works hard, and when it fails the control loses the confirmation it needs.
The check order this code implies
- Power the appliance down at the breaker and bring it back — Free, and it clears a latched fault.
- Note whether the fault is immediate or takes seconds — Immediate and delayed point at different halves of the circuit.
What you can do without tools
- Switch off at the breaker, wait, and bring it back up — Clears a latched fault and is the entire owner-side procedure for a microwave power fault.
About 10 min
- Try one short heating attempt with a cup of water — Water heating means power is being produced; water staying cold with the code showing does not.
About 5 min
- STOP HERE - do not open the microwave cabinet — This is a service call at this point, with no exceptions.
Read this before touching anything
Safety
Stop at the cabinet on this one. The capacitor inside a microwave power circuit holds a lethal charge after the appliance is unplugged, which is why every owner-side step above stays outside it. Unplug the appliance or switch off its breaker before touching anything, leave the door interlocks as fitted, and call rather than open.
When a reset is not the answer
Call as soon as the code survives a power-down. A microwave power supply is not an owner repair at any level of experience: the capacitor stores a lethal charge after the appliance is unplugged. Stop using it and call now if you hear arcing, smell burning, or see scorch marks inside the cavity. Arcing inside a microwave cavity damages the waveguide cover and gets worse quickly.
Sibling codes
How far this page applies
This page is the appliance-class reading of one code, for the microwave and combination model lines that use this power supply. It stops short of model-specific figures on purpose: those differ by family, and a plausible-looking wrong number is worse than none. If your model has a page of its own it is the more specific answer and is linked from the code index below; use this page as the general orientation.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
