Phrasal Verbs with 'Power'

Power down

Cut the electricity supply to a computer or electronic device

Example: I POWERED DOWN my computer and went for lunch.

Power off

Cut the electricity to a computer or device to turn it off

Example: You mustn't POWER it OFF while it is updating.

Power up

Turn a computer or electronic device on so that it is ready to use

Example: I POWERED UP my laptop and started work.