Nonresponsive, will not boot, in short, I have SWOD

Last night my iPhone dropped all bars and froze. When I took it back into my dorm and plugged it into my computer it restarted and now hangs at the apple logo for 5 minutes then restarts. I assumed it was my power button since that had screwed up and removed it, yet, same problem. Also, my computer will NOT recognize my iPhone, so no DFU, the phone does not respond to me at all.

It turns on at will when plugged to a power source and reboots till it's dead.

I just purchased a power button but was wondering what you guys think. Are there anyways for me to test this without a power button being there just to be sure it's the power button? Thanks.