The machine will not start up

Yes, the motor has burned out.

The motor is here

https://www.partswarehouse.com/Bissell-Big-Green-Complete-Deep-Cleaner-Vacuum-7700-s/6667.htm

and at other fine emporiums of vacuum heaven.

https://www.google.com/search?q=Bissell+Model+%237700+replacement+motor

..

take it to a repair shop
something is jammed in the impellers section or the motor is burning out

take it back to service agent as maybe they forgot to reassemble and make them fix it as you've paid for a service.If you try to reconnect could fry whole thing or shock yourself.

dont no if this one is the same ,but it may help you, click the link below
http://www.youtube.com/watch?feature=player_embedded&v=1sSVIu6arbY#!

Sounds like the motor is either frozen or the machine is frozen. Humming means the motor is trying to turn. Is there an external hand wheel which will allow turning the machine by hand? If the machine has been in storage for a long time, the lubrication can become 'glue-like' causing difficult turning. This may require a trip to a service shop--hope this helps!

It could just be a slipping belt, hair and lint get under the belt and make it stretch the it slips and the spinning drive post heats it up until it starts burning.

honestly I found one on craigslist.. Now I'm not sure if you will have any in your area but I lucked out and found one. Hope this helps

if the motor doesn't run sounds like you either have a bad motor or your motor armature might have gotten wet and created a dead spot.if you have any contact cleaner spray a little on the armature then turn the motor by hand make sure its uuplugged first if you can turn the motor then plug it in and try to start it

Is the overfill valve (the yellow thing) in the waste container stuck in the up/full position? Maybe it just needs to be rinses well to avoid it being stuck and shutting off the vacuum portion of the cleaner.

Maybe this picture will help: