i got a cheap mistic, and 4 (would be 5) pre filled cartomizers. i used them all then cleaned them all because i planned on getting new juice. i got my juice yesterday, it's 80PG 20 VG. i refilled all 4 carts and there all fine except one. with this one, every time i take a drag there's no vapor. it makes the same noise it always makes when i take a drag (like a whistling noise) but no vapor comes out of it. it was fine when i first used it why isn't it working now?