My dryer hums when I try to turn it on but will not run it just stopped when my husband checked to see if the clothes were dry that was in it. What can be wrong with it?

Well the only thing I can possibly think of is the motor locked up on you or something in blower housing could be locking it up try checking that first save you time and money

peapops - here is a list of the probable causes:: #1 -no power at the power cord at the walloutlet;; #1a- check the screw in fuses or the double breaker for the dryer::: #2 - defective door switch :: #2a -test dorr switch with a volt ohms meter that is capable of doing 220 volts you will see the door switch under the top of the dryer cabinet< it will be a button or a leaver mounted to the inside of the cabinet:: make sure the power cord is disconnected and set the meter to rxi scale:: disconnect the wires comeing to the switch <then touch or clip the probs from the meter to the terminals the wires were hooked :: close the switch with you finger : if the meter reads zero ohms <the switch is good, if the meter reads high -it is faulty replace > :: hook the wires back up :: # #- open circuit in the power cord;; #3a- to test the power cord - remove the metal access plate covering the terminal block;; clip the probs from your meter to the cord plug( note -on a three wire cord the two outside wires in side the cord are the hot wires the middle one is the ground wire ) use a jumper wire . Hooked to each side of the cord (at the terminal block. Meter should still be set on rxi ohms scale ; if the meter reads zero cord is good <if it reads high or jumps then it is bad <and needs replaced : note _ as you are testing the cord bend it from top to bottom in a rolling montion :: #4- faulty start switch _ :: #4a- remove the top control panel: go to the start switch < there will be a couple heavy wires comeing to it , remove them . Now clip or hold the probs <one to each terminal : if the meter reads zero ohms< when the switch button is pressed in then the switch is ok , if it reads high ,it is defective ; replace switch;; #5-defective timer :: #5
A - to test the timer :: disconnect the wires comeing to it and clip the probs to the wire terminals < turn the timer knob to" NORMAL "dry ,if the meter reads zero ohms< the timer is ok - if it reads high ;then it is defective and needs replaced ::: #6 - make sure that all the wires you disconnect are reconnected ;; you already know about the motor >it may be defective < and will need to be checked ( tested ) i hope that i have hit the trouble and you have it fixed < if not come back on to this post and let us know : then it will have to be one or both of the items on the motor and i will tell you step by step of checking it (testing) that will be quite a job to do , it could be the centrifugal swuitch or the motor it self or can be both < if so the or it will have to be replaced :: if it is this then you will be removeing the top disconnecting support slides support rollers <the drum ect ect ;;
Good luck and stay safe , the 220 volts are not forgiveing and god bless :: f.b.e.