Cause
The box fan in the tub cover does not operate properly.
Solution
Check the Fan connector, and voltage to the fan (12Vdc).
With the dryer first starts the Box Fan will run for the first minute. In test mode the fan will run during the fourth, fifth and sixth presses of the start button.
If the Main PCB does not send 12Vdc to the fan replace the Main PCB. If there is 12Vdc from the Main PCB, replace the Box Fan.