A USB Cable With No Black Wire
A USB cable that does not have a black wire is not a standard USB cable. A standard USB cable has four wires – two for data, two for power, and a black wire. A USB cable that has no black wire is a power-only cable, and it should not be used for charging or data transfer. Green and white are generally used for Data. Typical usb cables usually have red and black denoting +ve and -ve respectively. Some cables utilize foil or metal coir winding in place of dedicated black wire
It is not asvisable to use cheap cable thin metal coir coming along with the insulation when stripping insulation off with clipper. Thin wiring causes more resistant results in more heat. Therefore it’s never recommend to use such cable for any purpose. You may pick another cable or even use thin shaving blade to dissect in a vertical way without breaking the metal coir mesh as well as use that as ground.
Suppose the cable is lacking mesh or black wire altogether. In that case, it might be some other proprietary connection cable. You may use in continuity/Led testing mode in Multimeter to check and reconnect using other pinout.
Identifying a data cable
One of the ways to tell if your USB cable is a data one is to check the D+ and D lines. The D+/D lines are the middle two pins of the USB connector. If they do not show up, then your cable is a charging cord and not a data one. If you have a multimeter, you can test the cable using the D+/D lines.
A USB cable has four pins – pin numbers 2 and 3 are differential data pins. These are used for sending and receiving data in the USB protocol. Pin number four is the ground pin. Each pin has a color coding. Red, white, green, grey, and black are used for data and signal signals. Using a pinout diagram, you can quickly identify which USB connector type you have.
A USB cable without a black wire is not a data cable. The USB standard does not allow for data cables without the data lines. They must have a shielded twisted pair of conductors to transmit data. However, if the data lines are missing, the cable will not charge.
USB is a common connection standard used to connect computers and peripheral devices. The cable is designed to provide the highest speed, accuracy, and error-free data transfer. There are three main types of USB cable: A, B, and C. USB type A cables are the familiar rectangular wires, while the USB type B cables are the small square ones.
Identifying a power-only cable
When it comes to power-only USB cables, you should know the difference between them and regular ones. Power-only USB cables provide a fixed amount of current, typically 100 mA, to the device you are charging. These cables are not compatible with smart charging devices, which negotiate the maximum amount of current during the USB enumeration sequence.
To identify a power-only USB cable, look for markings on the cable. Usually, a charging-only USB cable is two conductors in size and is labeled with AWG 22. Sometimes, a charging-only cable will have four conductors but only two of them are connected. In such cases, the cables waste copper.
Data cables contain four wires. These are the positive (+) and negative (-) wires, as well as the data transfer (D+) and data-receive (D-). If a power-only USB cable does not have these wires, you need to purchase a different type.
Power-only USB cables aren’t always clearly labeled, but you can easily identify a power-only USB cable by its thickness. Data cables are much thicker than their charging counterparts. They have four wires and a thicker outer lining. You should avoid using these cables on your laptop or mobile device.
While the product page of a USB cable should state whether it supports data and power exchange, the USB Implementers Forum does not have a standard for distinguishing between a power-only USB cable and a data-only USB cable. Often, you will find both types. If you’re unsure, ask the store clerk to check if the cable supports data exchange.
If you want to be sure whether a USB cable has data lines or not, you can use an “Is it me or USB?” tester. Simply plug in the cable into a USB-A port or a micro USB-B port to determine if there are data wires on the cable. The tester will flash two or four LEDs if there are data lines present.
Another type of USB cable is a hub. A hub can connect several USB devices to a host port. Some hubs can support up to 127 devices. A hub can have different depths and can also be used as an extension cord.
Checking for shielding
A USB cable with shielding can be a big benefit if you have a sensitive wireless device. This is because high-speed USB signals can interfere with wireless communication receivers, resulting in reduced wireless performance. Shielding also helps to minimize radiation. Fortunately, there is an easy way to test USB cables for shielding.
Check the USB cable’s shielding on both ends. The shield should be grounded to the chassis ground. If it is not, you can use a capacitor or r/c parallel network to create a parallel circuit between the USB and system grounds. If the shield is not fully shielded, it may have a short link and lose its shielding. This can lead to signal corruption.
Ideally, a USB cable has at least 60dB of attenuation between the shield and the signal. The signal is further divided by other cables and the ground. In the case of a 3cm wire link between the shield and the ground trace, the shield might do 30dB, while the ground trace might do 40 or 50dB. It’s important to use USB cables with shielding to protect against EFT.
USB data signals are sensitive to noise. If a USB cable doesn’t have a ground shield, it will introduce common mode noise. This noise will cause your device to drop packets, or even crash. Common mode filtering won’t help, either. If the shield isn’t shielded, your device will experience com failure, dropped packets, or even dropped USB communications.
Some cables have metal connectors, which don’t have shielding. They might have shielding inside, but it’s not inside the cable. Whether a USB cable has a shield or not depends on its environment. For example, in a busy retail environment, you’d want to pick a foil-shielded cable. Similarly, a copper-braid shield would be a better choice for an office environment.