I've had the tank for about a year and purchased several rebuildable coils. Things had been fine and then my istick Pico started showing the ohms fluctuating when I put on a new coil. Tried it on an older istick Pico and still had problems getting it work. I kept getting no coil or some other fault message, but ohms stayed steady when it did read the coil. After hours of fooling around with everything I finally got a coil to work. I purchased a new mod (Smoant Battlestar) about two weeks ago. Things worked great! Went to change the coil today and now it's not reading my coils. It's got to be the tank! I've tried pushing up the pin on the bottom of the tank and that didn't help. 5 of my 6 rebuildable coils don't work. Even a prebuilt coil didn't work, but I found one that is working. Any advice? Can I get a new center pin from somewhere? Does something happen to the metal pin (oxidize)? This just seems so weird.