Hi to everyone, as the object i have an issue with this box of overheating. My normal range is single coil about 25/30 watts in ss316 or kanthal and .35/.40 ohms. I try to change new battery (18650 sony , lg ,samsung ) ,some atomizer (griffin , zephyrus , kanger) , loosen the cap , unscrew the contract screw , loosen tighten the catode screw, firmware updated to last for DNA75,but nothing change , after 8/10 puffs the box became very hot especially in the zone indicated in attach file.Unfortunately i haven' t a 26650 battery to try. Any ideas? Tnx. P.s.Sorry for my poor english.