I loved my protank when I first got it. Not long after I started having an issue with it making contact with my batteries and firing. I got some advice thanks to ECF and was told to slightly pull down the center pin on the protank coil, and it worked!...for a bit. Since then I have been super careful not to overtighten the protank on my batteries. Even after the fix, I kept having to adjust it while vaping because if I only tightened it enough to make contact it would loosen on its own. Now its stopped working again completely. I've tried two different coil heads on two different batteries. Ugh! Is there any hope??