The DIY Guide to Leads and Cables for Phone Chargers and Docks

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The DIY Guide to Leads and Cables for Phone Chargers and Docks

Sometimes the right charger or dock for a phone is just too hard to find. Taking the DIY approach is a great way to find a charger or power cable for any appliance, while still keeping the cost of such an item to a minimum. With just a little skill and knowledge, even the least experienced reader will be able turn many of the broken leads and cables on the market into electrical gems. The guide below will explain how.

Tools Required

As with any DIY project, a few tools are required before attempting to repair any electrical equipment. The table below gives some information about the most useful items to have around a workshop before beginning a project such as this.


Tools Required


Digital multimeter

The most important tool for any budding electrical hobbyist is a digital multimeter. This handy device can be used to detect the voltage and current between the terminals of a cable, allowing for informative tests to be performed on a broken item. The newer models often feature an inbuilt continuity tester to allow the user to test for breaks in the circuit detect short-circuits between the terminals. When dealing with electrical equipment, though, it is of critical importance to read and understand the safety instructions provided with a digital multimetre, and be completely sure of how to use it.

Soldering Iron

A soldering iron is the key to performing lasting repairs on any electrical device as it allows a permanent contact to be made between broken wires, and allows terminals to be held in place within a circuit board. Cheaper soldering irons can melt with excessive use, so investing in one of the higher quality irons available usually proves a wise choice.

Wire snips

Wire snips provide a clean cut though both the metal core of a wire and its plastic coat; a must for any safe repairs on a cable. Wire strippers may also be a good investment for cleanly and accurately stripping the plastic coat from a wire without harming the metal core inside.

Helping hand

To create a soldered joint safely, it is important to hold the target components in the correct orientation. A set of helping hands is a great way to ensure that any component can be held steady while maintenance and repairs are performed on it.

Electrical tape

Electrical tape is commonly used to temporarily insulate components or wires from each other during repairs, and from contact with outside objects, or the user.

Heat Shrink

Heat shrink is often the safest and easiest way to insulate a bare piece of wire, while still maintaining a professional look. While electrical tape is suited to performing rapid repairs on a piece of wire and insulating it temporarily, heat shrink is a much more permanent solution.

Glue gun

A small glue gun is another potential solution to insulating a component or wire, since a layer of glue can be moulded to exactly the dimensions of the connector in question, and used to secure the fragile parts of the component as well as to efficiently insulate them.

Isolating the Problem

Before attempting any repairs on a device, it is important to isolate the problem preventing its correct operation. The most common problems associated with small appliance chargers is a break in the metal core of the wire, usually occurring at the point where the wire meets the connector to the device since this is the point which often bears the brunt of harsh use. Begin by checking the cable for signs of wear such as a damaged plastic casing or bulges along the wire. These obvious signs of excessive wear are points at which initial diagnostic efforts should be focussed. Plugging the charger into the wall, measuring the voltage across the terminals, and manipulating the wire at the points of wear to assess any change in voltage is a good place to start. If the output voltage is zero when the cable is relaxed, but returns to normal when the cable is bent into a specific conformation, there is likely a break in the cable’s metal core. If the voltage is constantly less than normal, then the problem is likely with the transformer. If the voltage is constantly zero irrespective of cable manipulation, the issue is either with the plug or the transformer. Unplugging the charger, cutting the wire about 5cm below the plug, stripping the wires on the end coming from the transformer, and testing as before (this time measuring the voltage across the wires instead of across the terminals of the plug) will allow the problem to be narrowed down to either the plug or the transformer.

Performing Repairs

The following sections will explain the simple repairs which can be performed on most cables at home.

Plug Fault

Plug faults are surprisingly uncommon, since the plugs are often quite sturdily built, but simple plugs can be repaired by cutting the plastic insulator off, de-soldering the connections, cutting approximately 5-10cm of wire from the end, and re-soldering the remaining wire to the plug (making sure to pay attention to the polarity of connections before re-soldering: place an electric tape ‘tag’ over the negative wire if they are not labelled as such). Standard DC plugs can also be purchased from an electronics shop or online. Make sure to insulate the connections appropriately after re-soldering each of the joints.

Cable Fault

Cable faults near the middle of the cable can often be repaired by removing the damaged section, soldering the two ends together, and insulating the connections once more. Faults extremely close to the plug may require repair as directed above for a plug fault, depending on the closeness of the cable break. Problems with the cable where it meets the transformer are less common, as this section of the cable is much less mobile than the other sections discussed here. A repair of this type, however, may require soldering of very short connections, since opening a transformer is exceedingly difficult.

Transformer Fault

Any problem with a transformer is incredibly difficult to diagnose and repair without specialist knowledge. In addition to this, the transformers are constructed in such a way as to prevent users from opening them in an attempt to perform DIY repairs. It is, therefore, often unwise to open a transformer due to the possibility of causing irreparable to damage to the transformer, and perhaps shorting out the mains supply, thereby causing fire or electrocution. An alternative solution is to purchase a working transformer of similar specifications; perhaps a similar phone charger with a different problem. The cables can be cut and the two appliances grafted together in a similar way to that described above. It is important to ensure that the voltage rating shown on both chargers is the same. Supplying a device with a higher voltage than it is designed for will often irreparably damage the expensive device. The current rating is not so important; this rating is simply the maximum current the transformer is capable of supplying. The device tends to only draw what it requires during normal use, but it is important to choose a transformer with a maximum current rating greater or equal to the standard charger supplied with the device.

Finding Broken Chargers on eBay

To find broken chargers on eBay, searching for ‘mobile phone charger’ yields a huge variety of results which are not specific enough for these purposes. To obtain more useful results, it is necessary to refine the search using categories. Begin by clicking on Mobile Phones & Communication under ‘Electronics & Technology’ on the homepage. From the pane on the left of the page, click Mobile Phone Accessories, and perform all further searches within this category. Here, a search for charger yields a mixture of new and used appliances. Selecting For parts or not working under Condition on the left now supplies a comprehensive list of the broken chargers and transformers eBay has to offer.


eBay is a fantastic source of used goods, and can be the perfect place to find broken mobile phone chargers which the sellers are unable to repair themselves. Armed with the information above, any novice electronics hobbyist should be able to cash in on the bargains available by scavenging for parts and repairing broken chargers, and saving a few pounds in the process.

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