My humidifier My Sunbeam model 700 Ultrasonic Humidifier runs, but does not produce any mist. I removed the water tank while it was running and could see water bubbling up and a little mist being produced from the little silver tab in the bottom. Is there anything I can do to remedy the problem?

SOURCE: Humidifier mist won't come out of tube

sounds like the small fan that is located in the base isn`t pushing the mist out. unplug it then take all the screws out of the base. there are screws under the black foam stands too. be careful not to touch anything that looks like live wires while you look inside then look inside while it is pluged in. it should turn. check for something blocking it like lint or dirt..you may be able to clean around the shaft with w d 40

SOURCE: sunbeam ultrasonic humidifier runs but produces no mist

It sounds very much like the transducer has failed. This is likely a crystal transducer and since they produce the agitation that should cause a mist, they are running continuously; not a good thing for something that is trying to shake iteslf apart all the time. These require input from a circuit that produces the fairly high level of power needed to drive the crystal so it could also be the source of the problem.
This isn't something an owner is able to diagnose unless they have some technical training.     

SOURCE: Need parts for Sunbeam ultrasonic

I see you have been waiting on a response for some time and I suggest you contact Sunbeam (if you haven't done it already) at their website for Canada:
Sunbeam Canada Customer Service