Hi, i had recently purchased a used M401 e-cig from some guy. I tried them both when i got to my car, but when i got home, one of the atomizers wasn't working. When i inhale: the LED lights up, but the atomizer does not get hot, nor does any vapor come out. What should i do? I don't have much tools on my hands, so i was thinking of cleaning it. How do i properly clean it?