How do I unclog my fog macheine? I had a Halloween participant last year and purchased the Visual Effects...

I had a Halloween participant last year and purchased the Visual Effects Super Fogger V-950 (around 300$) I used it once poured out the remaining fog solution and stored it over the summer. I plan on having another do this year.. took out the fogger and it produced no fog what so ever.. I don't know if it is clogged.. I can't find manufacturer information.. I be wondering if any one had any effective ideas..
Thank you!
Answers:    within should be an adjustment knob, for the amount of fog ,you want, or a off on spout,
what liquid is used for the fog ? does it have a varnish base, or sea base, try fogging some wet , [dump out other liquid first]