DIAGNOSIS A totally dead unit almost always points to a power issue, not a complex internal failure. The first suspects are the outlet or the cord.
FIX Unplug the cord from both the wall and the back of the Instant Pot. Check that the prongs on the cord aren't bent. Plug the cord firmly back into the port on the appliance—it can feel a bit stiff, but you should hear/feel a solid click. Now plug it into a different, known-working wall outlet. Don't use a power strip or extension cord if you can avoid it.
IF THAT DIDN'T WORK The thermal fuse inside the base might have blown, which is a safety device. This can happen if the pot overheated severely. This isn't user-serviceable. You'll need to contact customer support for a base replacement.
HEADS UP The Duo Crisp has a separate power connection for the base and the air fryer lid. If the base has power (lights on) but the air fryer functions don't work, the issue is with the lid's connection to the base or the lid itself.