Heat fuel air.
Sometimes as mentioned the pellets need to be Blended with other types of smoke to work. It was either cherry or apple, and charcoal I have problems with.
Next lite your amps outside of your smoker and allow it to burn a min. of 15 mins. unassisted. That means after you are finished blowing and lighting and fanning or whatever you find that works best for you. If it won't burn outside, no way it will burn inside. I usually set mine and lite it where it will catch a breeze.
If its lit and smoking well and you insert it in the smoker (whatever kind you have since you didn't mention one) that has already been preheating, open the exhaust vent full open, and crack the suction vent to allow the unit to draw the draft thru the smoker. If you have not preheated you may fail to achieve pulling the draft. No draft, no air, no smoke.
Think about it this way, you are using the AMPs to give you 4 to 18 hours (if regulated properly) of smoke, 30 mins isn't too much to ensure a proper smoke is it?
Its like everthing else in smoking, there is a learning curve. If you ensure its smoking outside the smoker, then it has to be the draft. If it will not lite outside the smoker, it maybe be the pellets. Those are the two biggest problems folks have, well that and over filling the pellet tray them.
Don't try to fill as much as possible, try leaving a little room before the top of the tray. That was my biggest problem till I figured it out.
Work with it, get it working before you want to use it. Spend 30 mins or a hour tomorrow just playing with it, its not a plug and play device. Find what works for you. Took me a while to get comfortible with it, and even then it still kicks up its heels ocassionally, usually when I take it for granite. LOL
Hope you figure it out soon. Remember if it smokes on the outside properly, that eliminates some of the possible causes. Preheat the smoker and insure a good draw thru the unit when placing the smoker in. Walk away and leave it alone for 15 to 30 mins. Everytime you open the smoker it changes that wind direction. Once you get good smoke, regulate your smoker's vent by whichever end you find easiest to reach, suction or discharge, but always the same end.
Its a load of fun learning and a cold beverage is allowed while tweaking it in. Don't take it to seriously. Its about the fun of learning and perfecting.
Bon Chance