Microwave will not heat and displays H98 shortly after pressing START.
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.
Possible Causes
How to Fix / Troubleshooting
Critical safety warning: H98 is a high-voltage protection code. Internal components can be lethal if mishandled.
User-level actions:
- 1. Confirm symptom: If the oven light and turntable work but food does not heat and H98 appears, the HV system is at fault.
- 2. Power cycle: Unplug for 10 minutes, then plug back in and test once more. If H98 returns, stop using the microwave.
- 3. Avoid repeated attempts: Repeatedly trying to run the unit can damage the transformer/inverter further.
Service recommendation: Contact Toshiba service to diagnose the magnetron, transformer/inverter, HV diode, and control PCB. These parts must be tested and replaced by professionals only.