Roper Electric Dryer Heats but drum won't spin

Yank the filter out the top. Remove the 2 screws in the filter housing. Use a putty knife to pop the top and then remove the screws holding the front on. NOTE: raise up on the front panel slightly so you won't damage the bottom clips. Get the front out yer way and remove the drum. Clean out the dryer and oil the rollers and idler. Use this handy ROUTING GUIDE to see how to put the belt back.

I have a roper dryer and when I turnn the knob to any setting it makes a noise as if it is getting an overload of electricity. The heating element heats up but when I push the button for it to spin it will not spin. I took the back off and cleaned evrything real good and checked all the wiring. put it back together and it worked fine to dry one load of clothes but now it is doing the same thing.