Axial thermal fuse, a one-time cutoff that opens when it overheats

Thermal cutouts and thermal fuses (TCO)

Thermal cutouts open when a part gets too hot. Some reset themselves when they cool; one-shot thermal fuses must be replaced. A blown cutout is a symptom: always find the overheating cause (blocked vent, failed fan, stuck relay) before closing up.

Cross-checked ~20 min easyBrands: All

Before you start

Unplug before testing
Microwaves: follow the HV discharge procedure before reaching inside
Never bypass or jumper a cutout, even for a test run

Diagnostic steps

Unlock all 4 steps with expected values

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OnCall Tech is a reference tool for trained technicians and can make mistakes. Always disconnect power and confirm with the manufacturer's documentation before you work.

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