Try another coil if possible, if not then see below
Take the entire tank apart, put the coil one side, clean all the rest. Now screw the base of the tank gently onto your mod. Then gently screw your coil into the base. Test and see, should work now. If not, check the coil and see if the little...
You guys see what smok is doing right? Quite clever actually. Looks like they are making smok versions of loads of the popular mods out there.
AL85 vs eleaf pico
Stick V8 vs ijust S
Q box vs nugget / minivolt/ target mini / etc
So the q-box looks like a nice little stealthy vaping setup right...
And you checked for juice in the base again?
Also just had another idea. Try assembling your tank bit by bit from the base and upwards ON the mod. So tighten base first, then rba coil, then etc. Just hold onto the base of the tank for all the upward bits so you don't overtighten your tank base...
Sometimes it's the big baby beast rba oring that causes the hassles. Sometimes you have to replace the oring or even add another one on top of the old one as the original perishes or is not thick enough so when you screw the rba into the base it pushes the 510 pin down too far and you get shorts...