I have a SmokBox VariCool that has performed flawlessly since I purchased it a few months ago. It has been a little flaky for the past few weeks, though I mistakenly thought it was my cartos/clearos since the problem was intermittent. Now I am quite certain that the issue is with the unit itself. I cannot get anything to fire (cartos and clearos that do work on my KGO), and I get no voltage (multimeter) from the SmokBox's 510 connector. The batteries are at 4.19v and the red light goes on when firing, but nothing comes out. Could this be a fault at the 510 connection? The unit has suffered no significant drops other than occasional tipping over on my desk, and given the hot-glue securing of wires inside, it seems unlikely. Any ideas? Thanks.