Ok, have you tried the roll crimp? I'm pretty sure the green is pre-3.1 so it probably wasn't done.
But before you do that, try this:
First, with the head off the body, rig the head to a battery with a paper clip. If it works, then something is wrong with the body to head contact.
If not, try this:
Take the head off and short the solder blob to the threads with a paper clip or wire or anything metal for about ten seconds (to discharge the capacitor). Screw the head back on the tube w/battery and see if it works. If it does, it may be an internal circuit problem. I've been doing some tests on an intermittent unit and that seems to be the problem. The cap. is charging up too high at .62 volts when the norm. is .34 volts. The light may then work until you turn it off and then not work again until the capacitor is discharged again.
If this doesn't work, try the roll crimp.
Let us know how it goes. Hopefully you can fix your avatar generator. /ubbthreads/images/graemlins/grin.gif If not, I think ARC will cover it under warranty.