I know this is an old thread, but after 2 bad coils in a clone kit which I took apart the top by the wick, and the coil looked like the metal on these were touching each other and were blackened(so my guess is yes 2 bad coils out of 3) I have one spare which I untwisted the wicks as DaveP suggested(there were four wicks on these) so far so good. I may have to get the real deal Vision Mini Vivi now. The thread on this clone one are fussy and the metal is so much cheaper than the named brand clearomizers that I have.