Cooling fan runs continuously or does not run at all; oven may shut down with an error during use.

Safety first: Disconnect power and allow the oven to cool before accessing the fan.

• Check fan operation: With the oven reconnected and set to a moderate temperature, listen for the Toshiba cooling fan at the top/rear. If it never starts, turn power off and proceed with testing.
• Inspect fan blades and housing: Remove the top cover to access the cooling fan. Clear any insulation, dust, or debris obstructing the blades. Ensure the fan spins freely by hand.
• Test fan motor: Disconnect the fan and measure its resistance. An open circuit indicates a failed motor. Replace the cooling fan assembly.
• Check control output: If the fan motor is good but never receives voltage, the fan relay or triac on the Toshiba PCB may be faulty. Replace the control board if the output is dead or stuck on.
• Sensor check: A faulty sensor reading may cause the fan to run constantly. Test the cavity/PCB sensor as per Toshiba specs and replace if out of range.

Do not operate the oven without a functioning cooling fan; this can overheat internal components and create a fire hazard.