You can get replacement AC power cords by contacting the device or appliance's authorized service center and asking if they carry replacement power cords for your device's specific brand or model. Most hardware and home-improvement retailers also sell AC power cords that match the wattage, voltage and ampere requirements of a variety of broken power cords.
Authorized service centers usually carry replacement parts, such as power cords and adapters. Many service centers replace damaged cords without charge if the product is still under warranty. If the power cord is not removable, take the device to the service center, and have a licensed technician replace the old cord.
If the service center does not carry or sell replacement parts to end users, check a hardware or a home-improvement retailer, such as Home Depot and Lowe's, for replacement parts. To make sure that you are getting the same AC power cord, take the damaged cord with you and inquire whether the store carries the same cord or a cord with the same specifications.
If the power cord is missing, check your device's voltage output, input, ampere and wattage requirements, and have a staff member help you find a similar cord. Some online retailers, such as Amazon and BestBuy, may also have a similar cord or plug. Make sure that the specifications on your device matches the power cord's before finalizing a purchase.