Just got one delivered (my first tc mod) and I can't seem to get it into temp control mode. Follow the directions, from standby mode, press fire and minus buttons but temp control never shows up. Display shows normal mode then goes into stealth mode. Repeat and it goes from stealth mode into normal mode. Using a new TFV4 tank (says rated from 40-140W) with triple coils at .22 ohms and 50 Watts. Battery's a Sony vtc-4. Before I send it back, am I doing something wrong?