Is Power Optional?
While working at Microsoft as a front-line tech, another tech who was having a major problem with a customer's system asked me for some help. I was known as the "hardware guy" since I built my own machines, etc. The computer would not boot, would not display anything, would not--well, anything at all.
After hearing the t-shooting steps that had been tried, I said, "The computer isn't plugged into the wall."
The tech went back to the customer and asked him to make sure the system had power. The customer blew-up at him (I'm sure you've all had the experience) and let him know that he was a doctor and not some ignorant doofus off the street, and the problem was Windows and so forth. A week went by like this, and finally the tech asked the customer again to check that the computer was plugged-in.
You can almost certainly guess the answer. No, the computer was not plugged-in.