Diagnosis
This is usually a power supply issue, not a machine failure. The most common culprit is the basket not being seated all the way in, which activates a safety switch to prevent it from running empty.
How to Fix It
First, unplug it. Pull the basket out and look at the bottom of the cooking chamber. You'll see a little plastic nub or pin in the center. That's the safety switch. Now, take the basket and really push it back in. You should feel a firm, positive click when it's fully seated. It takes a bit more force than you might think. Once it's clicked in, plug the unit back in. The power light should come on.
If That Didn't Work
Check your outlet with another appliance. If the outlet is good, inspect the power cord for any damage. Also, make sure you're not using an extension cord or power strip; this unit needs to be plugged directly into the wall.
Heads Up
Always make sure the basket is clicked in before you try to set the time and temp. If it's not, the unit acts like it's dead, which can send you down a rabbit hole.