The short answer
A microwave that trips a breaker, sparks inside, or smells of burning is telling you something is wrong now rather than developing. On the TM family the correct sequence is short: unplug, do not reset repeatedly, do not run it again to reproduce the symptom, and call.
What you observe on these models
- A buzzing or crackling that is new — Worth stopping for even without a visible spark.
- The appliance trips the protective device rather than the breaker — An earth-leakage fault rather than an overload, and a different investigation.
- Smoke, however briefly — Unplug at once and do not use it again, whatever it looks like afterwards.
- The fault started after something boiled over or after a clean — Moisture and residue in the wrong place cause exactly this, and it does not clear by drying alone if a surface is damaged.
- NEAR MISS - heat but no sparks and nothing tripped — If it heats and behaves normally, look at the heating and start pages instead.
Causes, most likely first on the TM family
- Arcing at residue, foil or damaged coating — First on the four models below. Almost everything owners see as a dramatic electrical fault starts here, and the fix for the mild version is removing what is arcing before it burns a mark.
- Waveguide cover damage — Second. Once it is charred it keeps arcing at the same spot, which is why the marks are always in one place.
- Internal high-voltage breakdown — Third, and the version that trips breakers rather than sparking visibly. Service call, cabinet stays on.
- Supply side — Last, and worth one free test on another outlet before assuming the appliance is at fault.
Check in this order, and why
- First: separate the dish from the appliance — Sparking that only happens with one container is the container. That single test resolves a good proportion of these calls on the TM family.
- Second: inspect cold and unplugged — The cavity walls, the cover at the side wall, and the door frame. Burn marks tell you where the arcing is happening.
- Third: check the outlet where the model is portable — A different circuit either exonerates the supply or names it, and it costs nothing.
- Fourth: leave it unplugged and call — Anything past inspection on the four models below is behind the cabinet, and the cabinet must not come off.
Before you open anything
Safety
Unplug at the first sign of arcing, smoke or a burning smell, and do not use the appliance again to check whether it repeats - every repeat burns the damage deeper. The cabinet must never be removed; the stored charge inside is lethal after unplugging. A standard household branch circuit is 15 A or 20 A, which is more than enough energy to start a fire at a damaged connection.
Models in the TM family
Reference| Model number | Family key |
|---|---|
| TM044E6V-S0MAK1 | bosch:microwave:tm |
| TM044E6V-S0NAK1 | bosch:microwave:tm |
| TM062A2TG-P0HD | bosch:microwave:tm |
| TM944E6V-SHNDE0 | bosch:microwave:tm |
When to call a technician
Call after the free elimination: a metal-trimmed dish, foil, or a visibly charred cover. If none of those explains it, or if the appliance trips a breaker or smells of burning, it is a service call and the appliance stays unplugged until the visit. On the TM family there is no further owner step and the cabinet must not be opened.
Other faults covered for the TM family
Lead Appliance Repair Technician · 12 years experience
Experienced technician with 12 years specializing in washing machine and dryer repairs across all major brands.
