Hello Murhy91,
If your power went out and the plants weren't getting water for a couple of days, that will do it. One of the big drawbacks with
aeroponic systems is the plants die quickly if there's a power outage. I would pull the plants, clean and sanitize everything and start over. Even if you do get some of them to come back to life, pathogens have likely begun to get a foot hold on the roots in that amount of time.