The start button is not required and dryer comes on when dial is turned to auto dry. Also when finished the buzzer does not shut off until door is open. Is this a start button problem, or timer problem?
having the model # would help considerably as it is a great reference… but you could have a stuck start winding as well as a start switch stuck closed too… ( check to see if the start switch opens / closes with an ohm meter … button depressed circuit closed or a value close to 1 on your meter and button not depressed , open circuit and value close to 0 on your meter.. )
replace the start button this should solve your problem..