I have had this happen on a couple of my older mods. See if there is an o ring around the center pin. If so, go to your local hardware store and pick up some o rings, I believe they are 000 sized. Gently pry up the center pin with a small flathead screw driver and remove the old o ring. Place the new o ring on the tip of a pair of hemostats and open the hemostats to spread the o ring enough to roll it off and push it on to the center pin. This should help to keep your center pin positioned and prevent
juice from leaking down into your device. I would buy another mod anyway so you have a decent back-up device but I know the
subox has the same problem with the center pin. The Sigelei 75 is pretty good, but if you don't want to buy
batteries try the I stick 30.