The main board was a good guess on this model but there are more likely and far cheaper parts like the thermal fuse. The main boards are known to burn there motor relays up but it usually smells like burnt silicon.
The thermal fuse if more likely:Whirlpool WP3392519 Dryer Thermal Fuse - AppliancePartsPros.com
Unplug it. Pull lower access panel off, behind blower duct is a long white piece with 2 blue wires on it. That's your thermal fuse. If you have a multimeter test for continuity or no resistance. If your meter says oL or inf that's your problem. If you don't have a meter you can slip the 2 female wire terminals together and bypass the fuse, just make certain they cannot touch anything. You can wrap together in elec tape if possible. They will be live 120v when you try to start it and you'll get a surprise if they touch anything.
Alternatively you can put a meter lead on either side of the motor plug on the main control and try to start it. Smaller plug with back and blue wires. Prior to starting you should have 120v potential across the blue to black; indicating an open relay. If it closes when you push start your meter will read 0v or close. If it does not close you may have a bad door switch.
As to why the fuse opened? You may have a shorted element or blocked air duct in house; or it just failed. Order 2 in case, they are cheap and it sucks to only have one if it opens again in testing.