The short answer
Sparking, arcing, burning smells or a tripping breaker on a Bertazzoni SMD microwave are stop-now symptoms rather than diagnose-later ones. On this family the common causes are metal in the cavity, a damaged waveguide cover and food residue that has carbonised — and the response to all of them starts with unplugging the machine.
What an owner actually sees
- Visible sparks or arcing inside the cavity — Stop the cycle and unplug. Usually metal on the turntable or a burnt spot on the waveguide cover.
- Scorch marks or a burnt patch on the small panel in the cavity wall — The waveguide cover. Once it is marked, arcing concentrates there and recurs until the cover is replaced.
- A burning smell from the cabinet rather than from food — Unplug it and leave it unplugged. This is a component smell and there is nothing for an owner to inspect.
- NEAR MISS — the machine runs normally but does not heat — No heat without any electrical symptom is a high-voltage component fault rather than a safety event.
What it usually turns out to be, in order
- Metal in the cavity — First on this family and the most common cause of arcing by a wide margin. Metal trim on a plate, a twist tie, a fork left in a bowl, or foil on a package all arc, and none of them is an appliance fault.
- Damaged or carbonised waveguide cover — Second. Food spatter bakes onto the cover, carbonises, and becomes a conductive spot that arcs.
- Carbonised food residue on the cavity walls or the roof — Third. Long-baked spatter behaves the same way as a damaged cover.
- Failing high-voltage component or a shorted magnetron — Fourth. This is the burning-smell and tripping-breaker class, and it ends owner involvement. Unplug and call rather than testing.
Check in this order, and why
- 1. Stop the cycle and unplug the machine — Before anything else, and regardless of which symptom brought you here.
- 2. Look at what was in the cavity — Metal trim, a twist tie, foil, cutlery.
- 3. Inspect the waveguide cover and the cavity walls — You are looking for scorch marks and carbonised residue.
Read this before touching the appliance
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off, and in a microwave oven that charge is lethal — do not open the cabinet, do not attempt to discharge anything, and do not look for a fuse. Never run a machine that has arced until you know why it arced, never reset a breaker repeatedly, and never put metal of any kind in the cavity.
Models in the SMD family — The model numbers this page covers.
Reference| Model number | Family key |
|---|---|
| SMD2489ES | bertazzoni:microwave:smd |
Owner fix or service call
Call immediately, with the machine unplugged, for any burning smell from the cabinet, any smoke, any tripped breaker or any warm plug or lead. For arcing, clean the cavity and eliminate metal first — if it then recurs with a clean, undamaged cavity, that is a technician's job because the waveguide cover and everything behind it are not owner-serviceable. Do not keep using the appliance while waiting.
Nearby pages for these models
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