I'm working on an adapter, and was curious. Is the - ground and the + the voltage on the adapter? Or do I tie both together to get the voltage. I'm working on reviving a Gigabit Ethernet G4 from the dead by hacking together a power supply and then using a 28v wall adapter from an old printer. I dont have a voltmeter. Oh, and I'm guessing the cable with the white stripe is positive, right? I mean, there isnt much to lose if I f*** up, but still, I'd rather have this machine working again.