2clicker: oh man, oh man. I really hope you aren't having the same problems that I had. The simplest explanation for the problems I experienced, was that the universal adapter was threaded/twisted on too tight and ended up "pushing" the center post of the battery deeper into the body, so that later when I tried an omi or standard 510 cart on it with adapter, the pin was too low and never made contact with the cart. Unfortunately this problem is pretty complex as it's a few factors (lower pin not making contact, pin driving itself into body and shorting, solder wire possibly breaking off the post inside due to movement, etc), but it only takes one small oversight and overtightening to get into this weird situation. I can see how others might fall into the same trap, so thermovape if I were you I would put a FAT warning on the universal adapters saying not to twist them in all the way, etc. I think some units' center + pins are more fragile than others...
You mentioned the batt doesn't have LED lights on it? That makes it so hard to troubleshoot. Outside of teh thermovale rev, have any other carts on it worked since the initial failure? WIthout an LED it's hard to say.. but try this, thread the universal adapter onto the cart first, until it's bottomed out.. then thread the whole thing into your battery, but *super* loosely. Until the bottom post is just barely kissing and making contact witht he + terminal in the battery. Hold the button for 5-6 seconds and feel the dart to see if its getting warm. Repeat a few times. If no heat, either loosen or tighten the assembly and try again.. that's the best advice i can give right now but without a multimeter or a battery with LED on it, it's going to be tough