Selectivend 1B vends 1 can and won't vend more unless I unplug/plug machine.

[bajack]

This is my first and only machine, so I apologize for my lack of knowledge of these machines. However, my Selectivend 1B worked really well for several months then quit working.  I only use it occasionally, so it sits unplugged most of the time.

After I plug it in, I will vend 1 can. However, it does not completely "reset" and get ready to vend another. It passes all subsequent money through the coin returns and the rack that vended the can does not completely advance a replacement can.  If I unplug and plug in the machine, everything gets reset and my machine is again ready to sell me 1 can before I have to repeat the cycle again.

Any suggestions or clarifications are greatly appreciated.

-Brad