[quote name='norkusa']Call Microsoft and say you need a new one. That's what I did when I found a Xbox wireless adapter at Goodwill *without* a power supply for $4. I just told them that the one that came with it was broken (of course I didn't say I bought it used though). They didn't send me just the power supply but a new and complete wireless adapter for free.
Just tell them your 360 wouldn't power up, so you tried a friends power cord and it worked with that, so you need a new one ASAP. They'll almost for sure send you out a new cord or power supply after that, free of charge. That's what I did and it worked for me.[/QUOTE]
I called 1-800-4MY-XBOX and tried, but since my console was out of warranty and was manufactured in 06 and not 05, they said they couldn't help me unless I wanted to pay for a new power supply. And they don't sell the AC cables seperately.
Still open to suggestions...