you are trying to charge the charge pump through the bob, correct? have you spoken to Darek about it, he is really helpful. I would think it would work fine if you have everything setup correctly. To diagnose the problem you could use a chopped off printer cable plugged directly into the computer. Hook up your charge pump directly. If it still doesn't work, its not setup right in mach. If it works, it may be the bob. You could have a blown optoisolator or some other problem. Anyway, I am sure Darek will help you out.