Does it mean the USB cables are not pure copper or not thick enough?

[Matthew Wai]

I have a USB hard disk, which came with a USB to Mini-USB cable, which works properly.
I have three other USB to Mini-USB cables, which do not work with the hard disk, which simply does not spin although its LED is on.
Does it mean the cables are not pure copper or not thick enough?

 

[CountMike]

Could be either or both.

 

[BFG-9000]

USB to micro-USB cables at the dollar store specifically say 1.0A on the packages. This doesn't mean they are defective, just that they cannot move enough current without dropping voltage to charge a phone at 2.0A or run an external HDD. This resistance can be distributed (ie through the whole cable) or at one point (such as soldering only one strand to a connector because there's not enough room for more).

 

[Ninjawithagun]

It's not just the USB cable that is important. More importantly is what does the actual USB port support? Not all USB ports are created equally (i.e. USB 1.1 vs. USB 2.0 vs. USB 3.0, etc.). This is especially true when using laptops and older PCs where there may be only one or two ports that fully support USB 2.0, 3.0, and/or 3.1. USB C connectors are now available as well, but let's not include that as part of this discussion.

 

[Matthew Wai]

More importantly is what does the actual USB port support?

The USB 2.0 HDD came with a cable. The USB 2.0 port supports the HDD only if that cable is used.

 

[Matthew Wai]

This resistance can be distributed (ie through the whole cable) or at one point (such as soldering only one strand to a connector because there's not enough room for more).

If the wire is not pure copper, will the resistivity be higher?

they cannot move enough current without dropping voltage

If the wire is thin, will the voltage be low?

 

[BFG-9000]

Yes, but probably not enough to matter. The voltage is only low when under heavy load if the wire is too thin or long. For example my phone charger stops charging if USB falls to 4.2v

 

[Paperdoc]

I'm sure the issue is not the heaviness of the cable. It is in the type of USB port and the cable design, not the wire gauge.

USB2 standard ports can supply a device with up to 0.5 A current. With rare exceptions, that is NOT sufficient for any HDD. Even though "laptop external hard drives" were sold for use with USB2 systems, they contain HDD units particularly designed to consume minimum power. Additionally they normally had special arrangements for supplying the power needed. The straighforward way was to supply also a separate "power brick" that must be plugged into a wall outlet and into the HDD case jack. A more common way was to supply with the external drive a special USB2 cable with TWO plugs on one end. You have to connect BOTH of those to separate USB2 ports on the host computer to provide enough power to the drive.

The new USB3 ports can provide more power - up to 0.9 A. With the new Laptop External Drive units this IS enough to run the HDD units inside as long as you actually plug it into a real USB3 port using a USB3 cable. So these drive units do NOT come with a special two-headed cable. If you try to plug one of these into a USB2 port (and yes, the cable will fit) it will not get enough power and will appear to work "sort of", but will actually fail to read or write anything. If you use the wrong type of cable, it may also fail to work. So, use a true USB3 cable (like the one that came with the drive and DOES work) and plug it into a USB3 port on the host computer.

 

[Matthew Wai]

One day, if I want to buy a USB to Mini-USB cable, how can I ascertain, before purchasing, that it works with the HDD? My USB port does support the HDD, so the problem lies in the cable.

 

[Paperdoc]

As I recall, the mini-USB connector for USB3 IS quite different from the one for USB2. It looks a little like the USB2 connector, but with more stuff added on to one side. The metal outer sleeve around the contacts has a dip in it between the two sections. Likewise, of course, the socket in the drive unit is different to match. I believe the design is such that a USB2 connector CAN plug into the main portion of the mini-USB3 socket, leaving part of the socket unused. But of course in that case you on;t get full USN2 performance, especially on speed of data transfer.

The difference between USB2 and USB3 Type A (that "regular" ones) connectors is less obvious because they look identical from the outside. But if you look inside where the contacts are you see the difference. A USB2 connector had four contacts in a line across the support bar. A USB3 connector has those exact same four across the front, PLUS five more farther back behind those.

 

[James Mason]

Not all USB cables transfer data, especially "Charging cables" that you might buy for your phone, those only provide power, and can't send any data.

 

[Ninjawithagun]

Not all USB cables transfer data, especially "Charging cables" that you might buy for your phone, those only provide power, and can't send any data.

Every single USB cable I own transfers both data and power, albeit at different rates based upon the spec of the individual cable in question. The older USB 'power only' 2-pin cables are no longer produced. I'm sure if you look hard enough, you can still buy one, but why would you??

 

[BFG-9000]

Charge-only cables are great for charging devices from a PC, when you don't want to be annoyed by USB device connected sounds and popups every time you wake the PC. I do label them to avoid needless headscratching later, and wonder why they don't come prominently labeled.

They are also better for security hygiene because someone else's phone simply can't infect your PC, and public USB charging ports cannot infect your phone through them.

 

[Matthew Wai]

By Googling, I found the following:
https://www.amazon.com/AmazonBasics-USB-2-0-Cable-Male/dp/B00NH13S44/

Is there a way to find out whether it works with my USB 2.0 HDD?