the protank 2 is great for beginners! i had the same problems, a while back, with my protank 1.
my suggestions, (hopefully this helps!)
-unscrew the tank section (the way you would if you were filling up the juice)
-then unscrew the atomizer head and clean off the connection.
-screw it back in but this time tighter than you usually would (not too tight though)
-clean off the eco battery connection (the part that screws into the protank)
-use a small screwdriver or a medium sized needle to raise the center-pin (the connection) of the ego battery (almost as if you were using a crowbar to open a door)
-screw the whole thing (without the tank section) on to your ego battery (make sure you screw it tighter than you usually would
-now press the battery button, and if it fires then do a few dry burns (meaning pulse the battery for increments of 4 seconds untill the wick has no juice and the coil turns red)
-screw everything back together and it should work like new
repeat these steps regularly, like every 3 days
IF: the protank still doesnt fire, it could just bee a faulty atomizer,,, jjust replace the atty and it should be fine.. if that doesnt work, its probobly your battery. ivest in something like a Vamo or get into mechancals for rebuildables.
This sort of thing happens with these types of tank - battery configurations, just make sure everything is screwed in tight and cleaned. also remember to dry burn regularly!
i hope this helps