Unplug the unit. There wil be some phillips screws holding the back of the top lid on, remove them and push the top back and remove it. Restore power and test the unit. Look for an orange glow at the front right bottom of the machine. If all goes well it will be followed by a blue glow and heat. Unplug it again. Remove the two screws securing the control panel to the frame and push the front panel forward (it will not be easy as there are about five molded plastic keys which hold the front panel on) and up/off.
Remove all the wiring harness plugs to the control board (they are color-coded to make reassembly easy). You can them remove the four screws at the top of the main front panel and the two screws behind the door and pull the front panel out, remove the door switch plug and remove the front panel. If there was no orange glow during the test, there is a resettable high-limit switch on the left side of the burner tube which is probably now open, push it to reset and check the dryer's exhaust duct for obstructions. Let us know what you find, plenty more to check.