The short answer
Tripping, heat at the plug, sparks or a burning smell on an MOTR machine are the one class of fault where the first step is to stop rather than to diagnose. This machine is also the hood for the range below, so it collects grease that no countertop machine sees.
What you observe on these models
- The breaker trips when the machine starts heating — A supply pattern: the load is finding the limit of the circuit.
- A smell of hot plastic after a long cycle — Something is overheating.
- The panel behaves erratically after a spill — Moisture in the control area, and the machine should be isolated.
- The plug or the socket is warm to the touch — Poor contact under load, and it is a genuine fire risk rather than a nuisance.
- NEAR MISS — a hum that has always been there — A microwave is a noisy appliance, and an unchanged noise is not an electrical fault.
Causes, most likely first on the MOTR family
- Grease from the range below reaching the filters, the seal face and the vents — First on this platform: an over-the-range machine is also an extractor, so it collects what the cooking below produces.
- A shared circuit carrying more than it can — Second: a microwave draws heavily and briefly, which is exactly the load that finds a marginal circuit.
- An extension lead or a multi-way adaptor — Third: this appliance draws heavily and briefly, which is exactly the load an adaptor is least able to carry.
- Metal in the cavity — Fourth: foil, a metal-trimmed plate, a twist tie or a thermometer will flash and crackle.
- Running the machine empty or nearly empty — Last: with nothing to absorb the output the energy returns to the machine, which stresses exactly the parts that are expensive to replace.
Check in this order, and why that order
- Unplug the machine and feel the plug and the socket — Warm plug with a cool cord means poor contact at the socket, and that is a fire risk rather than an inconvenience.
- Note exactly when the breaker trips — On starting is a supply problem; on closing the door is a switch and fuse problem; at random is neither.
- Unplug it and look at the plug pins and the socket face — Discolouration or heat marks name the fault before anything else is tested.
- Clean the cavity roof and the cover of baked residue — Charred food arcs, and arcing damages the parts behind it.
- Check what was in the cavity when the sparking happened — Metal trim and foil account for most sparking reports.
Before you open anything
Safety
Unplug the appliance or switch off its breaker before removing any panel. A capacitor can hold a charge after the power is off. On this platform there is no check worth doing that cannot wait the thirty seconds it takes to isolate the machine properly.
Models in the MOTR family — The numbers this page covers.
Reference| Model number | Family key |
|---|---|
| MOTR14K3S-IS | avanti:microwave:motr |
When to call a technician
Proving a socket, moving the machine to a circuit of its own and keeping metal out of the cavity are owner work. On these models the line falls at the case itself, because of the capacitor behind it. Call without working through anything at all for a machine that died the instant a door was closed, which means a switch has failed out of sequence.
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