Article: Make sure it is completely unplugged before working on it. When it is plugged into an outlet, it still has an electrical current running through it. Be careful to avoid touching any exposed metal wires or contacts while unplugging the cord. Detach any other cords or electronics connected to the wire as well. If you're dealing with heavily-damaged cords, consider shutting off the electricity first. Shut off the fuse or circuit breaker. It is usually located in a secluded spot like in the basement or a storage room. Feel the entire length of the cord to see if it feels unusually warm. Look for any breaks in the insulation that could prevent the cord from working. Also, check plug prongs to see if they look melted or burned. Consider marking any damaged areas so you don't have to search for them later. If you see a lot of serious damage, you may be better off purchasing a new cord instead of attempting a repair. Note that broken extension cords cannot safely be spliced, or joined, back together. No matter how well you try to reconnect the old wires, the cord won't be safe for use. Instead, fit it with a new plug. Take the edge of the tape and place it over the broken casing. Then, wrap the tape around the cord a few times to seal the damage. Make sure it's well-sealed, then treat other damaged portions the same way. Electrical tape is a type of black vinyl that resists electricity, so it's great for safely wrapping up cords as long as there aren't any exposed metal wires. If the cord is so damaged that you see frayed metal, then you will most likely have to cut it to repair it. Tape is only good for insulating wires, preventing existing superficial damage to prevent it from getting worse. Another option is to fit a PVC shrink tube over the damaged portion. Heat it gently to shrink it and seal off the break. Other types of tape, including duct tape, can work. However, electrical tape is the best choice because it is designed to work on electrical components. End cutting pliers and lineman's pliers are a couple of options for cutting cleanly through electrical cords. Position the pliers past the damaged portion and sever the cord. Cut through all of the insulation and wiring with a single attempt. Then, do the same on the opposite side of the damaged portion to completely remove it. Check the length of each remaining cord. If they are pretty long, you may be able to reuse both of them. Throw away cut lengths that are too short to be useful. For example, you might cut an extension cord in half and reuse both parts. For smaller cords, such as from electronic devices, you may not need the shorter part even if it's reusable. Wire strippers are very useful for removing the cord's outer casing without damaging the wires underneath it. Measure from the cut end of the wire, taking caution to avoid removing more of the insulated casing than you need to. Clamp the pliers down to break the insulation, then slide it off the wire. Repeat this with the other half of the cut cord if you plan on soldering the pieces back together This will reveal the electrical wires inside the cord. Expect to see 3 wires in thicker cords like extension cords. Smaller cords, such as for household accessories, contain fewer wires. If you don't have wire strippers available, you could use a utility knife or another sharp tool. However, be very careful to avoid damaging the electrical wires. Score the insulation until you are able to remove it from the cord. Measure about 34in (1.9cm) from the cut end of each wire. Then, use the wire strippers to break through the casing. Slide the cut insulation off when you're done. It will expose the copper wires, which you can reroute to your replacement cap. The wires are a little smaller than the cord, so use wire strippers if you have them. Wire strippers are a better choice for precision than other tools, such as a utility knife, which can easily ruin the wires. If you make a mistake and cut through the individual wires, don't worry. Your cord isn't ruined. Just cut out the damaged portion again. If you're planning on soldering the cord lengths back together, strip the wires inside both parts.

What is a summary?
Disconnect the cord from the outlet. Inspect the cord for broken wires and other signs of damage. Repair superficial damage by wrapping it with electrical tape. Cut the cord on both sides of the damaged portion using pliers. Strip about 1in (2.5cm) of insulation off the cord with wire strippers. Remove insulation from each of the wires inside the cord.