Safety first: Disconnect power and wait for the oven to cool before removing the rear panel.

Access convection fan: Remove the rear interior panel inside the Toshiba oven cavity to expose the convection fan and cover. Then remove the outer rear panel if needed to access the motor.
Check for obstructions: Clean any baked-on grease or food debris from the fan blades. Ensure the fan spins freely by hand; if stiff or grinding, the motor is failing.
Test motor windings: Disconnect the motor and measure resistance. An open circuit or very high resistance indicates a failed motor. Replace the convection fan motor assembly.
Inspect wiring and relay: Check the harness from the PCB to the motor for damage. If the motor is good but never receives power, the fan relay on the Toshiba control board may be defective and the board should be replaced.

Do not run the oven in convection modes with a seized fan; uneven heating and overheating of components can occur.

Oven shows a fan error; convection fan does not run in fan-assisted modes, or runs noisily then stops.

Possible Causes