The power supply isn't delivering current to the printer.
FIX: Check the power cord connection at both ends. Ensure the cord is fully seated into the printer's power inlet and into a live electrical outlet.
IF THAT DIDN'T WORK: The printer may be in Deep Sleep mode, drawing only 0.6W with no indicators lit. Press the printer's power button once to wake it. If still dead, try a different power outlet and cord.
HEADS UP: The power consumption in Off mode is 0.03W. If the printer is plugged in but switched off at its button, you should see no lights.