and what a pile of rubbish these dryers are
by all means change the pcb
trouble is, the sensor bar is on the front of the duct (the 2 silver bars on the inside of the door )
sometimes, a good clean with alcohol based solution helps, they get coated with stuff
howvere if you watch the dryer with the door open, the stupid thing tumbles, and pushes the clothes to the back, therefore not touching the sensor
we’ve found leaning them forward slightly helps
pcb quite often cures it