Finding and isolating broken cables: How to safely repair defective cables

5 min

  • The most common causes of cable breaks are signs of wear, bruises and cuts. Cables from portable equipment that are frequently moved or coiled are particularly at risk.
  • Damaged cables are not to be trifled with: In addition to the risk of a cable fire, there is also the risk of burns and serious injuries if exposed wires are touched.
  • The cables of low-voltage devices (e.g. headphones) with a voltage of less than 50 volts can also be repaired by laypeople after a cable break, since an electric shock is not dangerous at this low voltage.

Cable break

Once you didn’t pay attention, it happened: whether you accidentally rolled the desk chair over the power cord from the laptop or the headphone cable was roughly wrapped, the danger of a cable break lurks in many corners of everyday life. But what now? Buying a new cable again?

Not necessarily: In many cases, you can repair a broken cable yourself. In this guide we will show you which tools you need to safely repair a defective cable and explain step by step how to proceed with the repair. To conclude our guide, we have put together a few tips for you to avoid cable breaks.

1. How does a cable break occur?

headphone cables are prone to broken cables

The cables of portable objects such as headphones are particularly susceptible to cable breaks.

A cable break can have various causes. While Signs of wear are more likely to occur in electrical devices with thin cables occur, it is often due to the careless handling of the cable by the user, which can lead to a break.

One time you don’t pay attention when working with the electric hedge trimmer and the misfortune has happened – the cable is cut.

Even jerky pulling on the cableto remove it from the socket, for example, has a negative effect on the durability.

Especially portable devices such as headphones or charging cables are particularly prone to cable breakage: If the cable is moved frequently, the inner conductors can be damaged, which in most cases results in loose contact.

Now, of course, the question arises whether it is worth repairing the device at all. In any case, find out in advance what options consumers have in the event of defective electrical appliances. In the case of old devices or very cheap electronics, the following applies: Here you can safely try out repairs yourself, as you basically have nothing to lose. However, it is imperative that you take the necessary safety measures for all repair work on electrical devices. The device should always be unplugged from the socket before starting repairs!

2. Why are damaged cables so dangerous?

burnt cables

Caution: Danger to life: Damaged cables must be replaced or repaired immediately.

As soon as you have identified a damaged cable and suspect a broken cable, this is the answer immediately removed from the socket and then repair it if necessary.

With low-voltage device cables that have a voltage below 50 volts, you are not taking any risk in trying to repair it. On the other hand, cables with a higher voltage should be used for your own safety completely replaced and not repaired independently become.

Under no circumstances should the damaged cable be left unattended in the socket, as curious children and pets could touch each other Burns and other serious injuries which, in the worst case scenario, can lead to deathto draw.

There is also the risk of a cable fire due to a short circuit. Therefore: Under no circumstances should you use damaged network cables, connection cables and the like. If the device is still in use, avoid touching exposed wires and insulation when removing the cable.

How to detect a broken cable in low-voltage devices: Sometimes the damage cannot be seen from the outside – to check whether there is a broken cable, you should first examine the defective cable carefully and feel it. Most of the time you can feel bumps that indicate a broken cable. Then connect the cable and move it carefully. If the cable is moved in the affected area, the device will no longer work properly and you can take further measures.

3. How do you repair a broken cable?

What do you need to repair a defective cable?
  • Carpet knife (possibly sharp kitchen knife)
  • Abisolierzange
  • Solder / solder and soldering iron or crimping tool
  • Squeeze connector
  • Shrink tubing

After you locate the broken wire, the first thing you need to do is remove the defective point. You can do this with a box knife or a sharp kitchen knife. For your safety, the cable must be disconnected from the power supply.

You can now simply cut out the defective area, making sure you work carefully. So that the DIY repair succeeds, the wires must be cut cleanly and evenly.

In the next step, use the wire stripper to insulate both ends of the cable evenly. This process is necessary to prepare the cable for the final soldering or crimping. After isolating, you can reconnect the wires. Use the color of the coating as a guide.

In order to finally connect the two loose ends together, the following are available two possibilities to disposal:

  • Solder: Use the soldering iron to heat the solder and apply it to the wires. Place the two ends on top of each other and heat the solder again. Wait for the solder to cool down and slide heat shrink tubing over the solder joint for insulation. Now the ends of the cable are firmly connected to each other again.
  • Crimpen: Attach the round plug and receptacle to the ends of the wires. Press the crimp connectors with the crimping pliers on all wires of the cable fixed. Finally, exposed connections are insulated with the shrink tubing.

4. Three practical tips to avoid cable breakage

pull the cable out of the socket

Not like this: Do not pull on the cable, but on the plug to avoid a cable break.

So that there is no cable break in the first place, you should use a few when handling sensitive electrical cables basic aspects regard:

  1. Storage: Avoid rolling up or kinking the cable too tightly. Careful handling is essential. Instead, store the cable in a practical storage box.
  2. Transport: Carried freely in the bag with many other items, the risk of damage to the headphone or charging cable is very high. It is better to transport the wired device in a separate bag or box inside a handbag or backpack so that it does not come into contact with other objects.
  3. Use: To remove the cable from the socket, never pull the cable, always pull the plug. The cable should also not be left in the socket for longer than necessary.

5. Dispose of electronic waste properly

The professional repair of electrical devices will not always be successful. If you fail to find the cause of a defect and eliminate it, all that remains is to dispose of it. And that’s problematic. Then:

Some of them are in electrical appliances toxic and environmentally harmful substances such as mercury in lamps and light sources. In addition, many electrical parts and circuit boards are built with rare and valuable raw materials. These include copper, gold, neodymium, and aluminum, to name a few examples. These fabrics can be recycled. For this reason, electrical waste must never be disposed of with normal household waste or with bulky waste. How to keep your old equipment as well as rechargeable batteries and batteries dispose of properly, explains the Federal Environment Agency on this overview page.

Photo credits: Adobe Stock / alephnull, Adobe Stock / pixarno, Adobe Stock / alexandersw, Adobe Stock / ihor_b (sorted chronologically or according to the order of the images used in the buying guide)


Passionate about DIY for over 10 years and all the new tools, I give you through this blog all my advice, tips, tests in all areas: carpentry, electricity, masonry, gardening, home automation ...


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