Kenmore dryer just hums, wont tumble - Kenmore Dryers

Try this:
Open door. Hold door button. Have someone push start button. When they push start button, spin the drum wiht your hand. If it starts working, the problem is the start windings in the motor are not being energized. Could be capacitor but not all motors use them. Could be the syntrifugal switch in the motor or something else in the starting system. May want to think about getting another dryer from a place like Lowes. They are usually around $200 and up for a good one.
Good Luck