sounds like it could be the motor going bad. you will probably need a 2nd person to do this but you will need to open the dryer door and hold down the door switch.. at the same time you'll need to push the start button and manually turn the drum by hand (all 3 of those at the same time) and if it fires up you've got a motor thats going bad but this will buy you a little time to replace it. even if it doesnt fire up that way you still probably have a bad motor unless there is something like a sock stuck in the blower wheel. does the dryer hum when you try to start it?