I have a problem with my 510 adaptor too. The 901 adapter that came with my device works great. I ordered and received a 510 adapter to use up all my 510 attys and not even one of them work with it. I also tried a Joye 306 atty and it didn't work either (same fittings). The 510 attys are the TW Titan type and a whole lot of the ones with not any brass showing from the outside except the ring (from LF, but they are the same Joye ones that most places have). All these attys work with 510 batteries. I don't think the center post is making contact. This is really hard to tell on the 510s, though, because the contact is all recessed. The attys don't seem to screw down to the bottom of the adapter. They run out of threading (on the atomizers) before center post contact is made.
Should I tap the center post from the top, or should I screw in and unscrew an atomizer really carefully until it finally makes contact, and if I have to do that, would I have to do that on every one, or just once - in other words, would it push the center post down on the adapter, or would it just do something on the atty?
I have made sure all the other contacts are working - I even took a wire brush to the top of the switch and bottom of the adapter to get all that "new brass gunk" stuff off, and I can test the voltage through the top of the adapter fine - just doesn't heat any atomizers.
Thanks for your help, everyone!