Symptoms
How this shows up
- Turntable rotates and display works, but food stays cold
- Fan and light turn on but no heat is produced
- Heating is much weaker than before
Diagnosis
Likely causes, ranked
1. Faulty magnetron
The magnetron generates the microwaves that heat food - if it fails, everything else can run normally while heating stops completely.
2. Failed high-voltage diode or capacitor
These components power the magnetron; a fault here is a common cause of a no-heat microwave.
3. Door switch fault
Safety interlock switches can fail in a way that allows the microwave to run but blocks the high-voltage circuit from activating.
Before you call
Safe checks you can do yourself
- Confirm the turntable and interior light work normally (rules out a total power failure)
- Test with a microwave-safe cup of water for 60 seconds to confirm the no-heat symptom
- Do not open the microwave casing yourself - high-voltage capacitors can hold a dangerous charge even when unplugged
Call a technician if:
- Always - no-heat faults involve high-voltage electrical components that aren't safe for DIY repair
Book a technician