How to be certain that the vacuum motor packed up?

Our vacuum cleaner would not start. I used a voltage tester pen to ensure the power reaches the on/off switch. The advise of Hwk April 2015 on this site helped me quite well open our 5 year old Nilfisk Multi 20 (Model No 107402045) vacuum cleaner. All other sited advised that it is to difficult for a layman to do ...
Nothing seem to block or cause the motor not to start - no debris. Now that I opened the cleaner what steps should I take to make very sure that the motor packed up? That is apsrt from checking the on/off switch.