Aurora R4 Power Supply Issue?

Hey guys, I recently moved houses with my Alienware Aurora R4 taking the trip too. I brought it out immediately from the car which sat overnight (20-30 degrees outside), plugged it in, and the fans and everything ran as usual for about 3 seconds then everything turned off, no weird noises. Tried to turn on again and the vents open along with the lights, but no noise, no fan whirring, no signal being sent to the monitor, nothing.

On the back of the tower where the power supply is is a little button along with a green light above it which I assume when held down will turn that green light on if the power supply is working. When I press the button/hold it down, absolutely nothing happens, no noise, no fans, no green light being lit. Would this signal that my power supply is dead? If so and that absolutely is the issue, I'll go grab a new one but I just want to make sure that that is most likely the issue. Any help is greatly appreciated, thanks!