I've got to say that I had the same thought as
simonsays - the insulator under the positive block looks fooked. Have you dry burned a coil or coils on it? If you did you may have inadvertently melted the insulator. The piccie isn't very clear but it looks melted to me, and it looks as though the positive block is touching the deck in the second photo. That'll do it.
As an aside, that coil in the first build is likely to short out - it looks way too high off the deck not to make contact with the chimney section. I may be wrong (and probably am!), but just in case, I thought I'd mention it.