My gas dryer is an older White-Westinghouse stack appliance, a DG250K. In the past I had done nothing more than change the belt on one occasion. The start button failed to start the motor on some occasions but then would mysteriously work again. Finally it failed to ever start. I changed the motor and the belt.
The dryer started again with the new motor, but it would not heat. I researched the dryer parts and purchased the coil set, the igniter, and the flame sensor. After installing the coils and checking my connections, the burner started. I decided to install the new flame sensor also, and I wanted to install a new igniter. When I carefully unwrapped the bubble wrap on that delicate igniter, I found it lost a piece in the bubble wrap. I tapped the remainder on my glass table to see if it would break further, but it did not. I suspect it may have been cracked before I received it, so I was relieved to see my original igniter was working. My old W-W will probably run another 25 years.
Changing the burner parts was very easy, and the videos were very helpful. Changing the motor took more time and was more difficult since the straps that hold the motor are very tight and are hard to remove and to replace on the new motor. I am glad that I did not resort to a repair technician. This site is the best that I have ever seen!