Last week I reported that the cart for my 3.5 DVCT died, and I ordered a new one. Got it today, refreshed my memory on filling tanks by watching SD's video, filled the tank, put a few drops in the top of the cart, inserted the DT, blocked the bottom, did 2 dry hits, put on fresh manual KD XL. Nothing. Just like what happened last week with the cart I thought died. Can not for the life of me figure out why I am getting no vapor, nothing. Tried on 3 different batteries, gave up and came back to work. Hopefully someone can suggest something