Oven shows a power supply or voltage error; may shut down or refuse to start heating.

Safety first: Turn off power at the breaker before accessing the rear terminal block.

• Check terminal block: Remove the rear cover and inspect the Toshiba oven's mains terminal block. Tighten any loose screws and look for heat damage or melted plastic. Replace the block if burnt.
• Verify supply voltage (qualified persons only): Measure the mains voltage at the terminal block. Ensure it matches the rating on the oven's data plate. If voltage is out of range, contact an electrician or your power provider.
• Inspect power filter board: Some Toshiba ovens use a separate EMI/power filter board. Check for burnt components or cracked solder joints. Replace if damaged.
• Control board sensing: If supply is stable but the oven still reports a voltage error, the sensing circuit on the control PCB may be faulty. Replace the control board.

Loose connections at the terminal block can overheat and are a fire risk; address them immediately.