I took it apart from the front and pulled out the drum and the front cover of the exhaust fan.
Then I found the fabric softener sheet that had been caught between the fan with some dust.
It was a great chance for me to clean up the dust and change some of the parts I ordered.
The defective part was Dryer Thermal Fuse. I spent extra time cleaning and changing the parts for the maintenance, so I wouldn't need to repair it for a while. When I changed the wheels, I put a little bit of lithium grease.