I came across this Dryer Booster Fan control switch completely melted and burnt out. The worst I've seen. In this case the only symptom of a problem was the booster fan wasn't working. In other cases there might be a burnt smell associated. It's not often that Dryer Booster Fans...
Dryer lint in flex hose
I came across this flex hose full of lint in an apartment in Vancouver last week. (July 25 2023) The residents had just recently gotten their dryer ducts cleaned. The duct cleaners couldn't get good airflow and suggested that the residents get a booster fan. So they called me in....