The short answer
A Contoure microwave that sparks, smells or trips its breaker should be stopped and unplugged before anything else, because arcing damages the oven every second it continues. On this class the usual cause is a coach supply or inverter unable to carry the oven, with metal, foil or metallic trim in the cavity next to rule out, and both are assessed without opening anything.
What you actually observe
- It trips on the inverter and never on shore power — A split by supply is a supply answer.
- The plug or the socket is warm after use — A failing connection and a fire risk in its own right.
- NEAR MISS: food heats unevenly with no smell or spark — That is a heating performance question rather than a safety one.
The causes, most likely first on this brand
- A coach supply or inverter unable to carry the oven — Ranked first on a Contoure unit: an inverter that cannot hold the oven under load trips or drops out, and the pattern is blamed on the appliance far more often than on the supply.
- Metal, foil or metallic trim in the cavity — Foil, a twist tie, a fork or a plate with a metallic rim all throw sparks in a microwave, and the damage from a few seconds of that can be permanent. Ranked second here: a compact coach cavity is used for quick reheating where foil is common.
- A damaged or soiled waveguide cover inside the cavity — Ranked third here: a small cavity puts splashes on the cover quickly.
- A damaged cord, plug or socket — Ranked fourth here: last, though a coach connection shaken by road miles does loosen.
Check in this order, and why this order
- Compare the oven's behaviour on shore power and on the inverter — A trip that only ever happens on the inverter is a supply result.
- Look at what was in the oven when the sparking happened — A metallic rim on a favourite plate is the version of this that catches people out.
- Look at the small panel on the side or roof of the cavity for scorch marks — Brown marks or a blistered surface there is the commonest cause of arcing inside a microwave.
What an owner can safely check
- Switch off other large draws and run the oven on shore power to compare — This separates a supply limit from an appliance fault with nothing opened.
About 20 min
- Take everything metallic out, including twist ties and decorative trim, and try again with a plain mug of water — A clean cavity with plain crockery is the control test.
Tools: mugAbout 10 min
- STOP HERE if the next step needs a meter on live terminals or a panel off — That is where an owner check ends and a service call begins.
Before you open anything
Safety
Stop using the oven and unplug it if you see arcing, smell burning or find scorch marks, and do not run it again to reproduce the fault. Never remove the outer cabinet: the capacitor inside holds a dangerous charge long after the power is off, and that is true of an oven unplugged for days. Never defeat an interlock, never run the oven empty, and never reset a breaker more than once on an appliance that keeps tripping it.
When to call a technician
Call as soon as the cavity, the crockery and the circuit are eliminated, because everything remaining is behind a cabinet that an owner must never open. Stop using the oven immediately, rather than testing further, if the small cover in the cavity is scorched or the door is damaged in any way. Bear in mind when you decide that an RV appliance is serviced by RV dealers rather than by household appliance technicians, and the warranty usually runs through the dealer who sold the coach.
Nearest pages of this class
What this page does not cover
This page covers the Contoure microwave as a class, not one family or model line. Component layouts, cavity materials and service procedures all change from build to build and are deliberately not here. Where a family or model page exists for your oven, it is the more specific answer and the one to read first.
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
