Oster
No power / primary power circuit failure
Microwave does not start at all; display is blank and no lights or sounds when pressing buttons.
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Safety Warning
This repair may involve working with high voltage components or water connections. Always unplug the appliance before removing any panels.
If you are not confident in your ability to perform this repair safely, we strongly recommend contacting a professional technician.
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Possible Causes
Blown internal line fuse, Faulty power cord, Tripped thermal fuse on cavity, Failed main control board power supply
How to Fix / Troubleshooting
Safety first: Unplug the microwave before removing any covers. Internal components can retain charge.
- Check outlet: Plug another device into the same outlet to verify power. Reset any tripped breakers or GFCI outlets.
- Inspect power cord: Look for cuts, burns, or kinks in the Oster microwave’s cord. If damaged, the cord must be replaced.
- Internal fuse check (advanced): Remove the outer cabinet and locate the line fuse near the power cord entry. Test it with a multimeter for continuity. Replace only with the same rating if blown, and investigate why it blew (shorted component or surge).
- If fuse is good and no power: The thermal fuse or main control board may be faulty. These should be diagnosed and replaced by a professional.
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Repair Difficulty
Hard
4/5
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