Ok so lately my SVD is reading "non" for ohms.. And the cartos are not firing. I put a smoktech dual coil on it and it read fine, but then when putting it in a tank with juice it will not read ohms, or fire. Funny thing is I never had this problem with my vamo or SVD. Then a got a pro tank to try, and now my vamo reads 9.9 ohms and won't fire. And my SVD reads NON and won't fire.. What can I do? This is really annoying. Please help.