I used this bravo rta for around 3 months, lately i had abad teast so i changeed my coils and cotton again but when i was pulsing to fire and try my cottons i notced that it turns into brown color so fast and I noticed this brown dots all over the build dick. I stoped using this RTA and started used my rda. Today I opened it again to check and the brown dots has been grown all over inside RTA can any one explain why this happened to avoid it in the future