Default [HELP] Download mode will not work

So I am trying to get my phone back to stock so I can send it back to verizon because my power button is no longer functional and when I try to go into download mode it goes to the screen with the yellow triangle just fine, I hit up on the volume it goes to the next screen for about a second then the phone goes off. I'm pretty much at a loss here on what to do, I just need to get my phone back to stock to send back, I am currently on notta's PA build.
GS3 : Trying to find a reliable ROM
ReZound : Newt's One XXX
Droid X2: Eclipse v2.0
Droid 1: Rooted Stock