How do you know power is at the outdoor unit? Did you check it with a meter? Check your breaker. If there's power at the outdoor unit, then shut the power and test your contacter. If the contacter has supply power then check the low voltage (24-28 volts) that operates the contacter, and if none check the low pressure cut-out,high pressure cut-out and make sure the thermostat is calling for cool. All ok so far, then test your capacitor. I forgot to mention to check for loose, broken, and disconnected wires.