Like all digital packets, I’ve collected a vast array of USB-C to USB-A cables over the years—but until recently I didn’t realize how many of them were dangerous to my electronics and destroyed them. should go. You might need it too.
Why destroy a good USB-C to USB-A cable? Well, it all goes back to the introduction of USB-C in 2014. The reversible connector was a big break from previous USB designs and was so complex, many cable manufacturers Didn’t know how to make a secure USB-C cable, In short, each cable should have a 56k ohm resistor. This lets your phone, tablet or laptop know whether the USB-C port is connected to the older class USB-A port.
If the device senses the 56K resistor, it limits the amount of power coming from the port. If, however, there is no 56K resistor, the phone or tablet assumes that it is connected to a high-powered USB-C port. In that case, the cable could potentially draw too much power from the port it’s plugged into, burning out the port, and sometimes damaging the connected device.
Gordon Mah Ungo
Good News? This problem was fixed years ago, and even the cheapest dollar store USB-C to USB-A cables I’ve recently bought were built to the spec.
The bad news is when you stumble upon an old cable that was built the wrong way. This may seem unlikely because this problem ceased to be a problem four years or more ago, but No one Always throws away useful cables. We all put them in a shoe box or wrap them in a coil and put them in a bag. Sure, I’ll occasionally e-waste the odd microUSB and miniUSB struggler along with old serial cables and printer cables, but USB-C rules the world. Even I don’t need the cable, someone else might. goes in the box.
So in the interest of seeing how many real bad cables I have in my own collection, I grabbed almost every USB-C to USB-A cable to find out how good they are. Turns out I’m a digital pack rat and I’ve accumulated no less than 43 cables.
only one cable was faster
You can see my test result below but one of the surprises was how many of my cables are absolutely terrible for transferring data. USB-C to USB-A cables can support USB 3.2 up to 10Gbps if they have extra wires. Without the extra wires, you usually get the native 40Mbps transfer speed of USB 2.0. This means that using a USB-C to USB-A cable for your NVMe SSD will result in a huge file transfer taking minutes instead of seconds.
Of the 43 cables I tested, only one cable supported USB 3.2 10Gbps speeds. Only one,
In addition to grading the cables on data transfer rates, I put them in bins based on the resistance of each. For the cables used to charge most devices, a low-resistance cable usually means that thicker or higher quality wires were used in the manufacture, and the device you’re charging has more power. Gets power.
The good news is that most of them were decent, but I found six cables that I threw in the “bad for charging” bin because the resistance was so high. As a practical matter, it may not make much of a difference in total charged time, but if a cable was being pulled, I needed a good reason for it.
You know a cable connector standard made it when companies really started butchering it by making cables that are literally charge-only cables. So it goes from USB-C to USB-A. Of my cables, I found four charge-only cables that only had wires for charging. Why make cables like this? The main reason is to save money to make them. But the only problem with charge cables is that they look very similar to charge and data cables.
Perhaps even worse, though, these charge-only cables actually register a lot of resistance. The irony is what makes them terrible charging cables.
But on the plus side, all the cables I mentioned so far were all wired correctly with 56k ohm resistors. Even the most dreaded charge-only cable will prevent your phone or tablet from blowing up the USB-A port on your laptop.
That luck didn’t last. The remaining 10 cables were made incorrectly. Five were made with the wrong wiring with the wrong 22k ohm resistor, or 56k ohm resistors. The remaining five had no 56k ohm resistors at all and should be classified as dangerous to use and possibly slated for destruction. These were the cables that raised red flags in 2015, and are probably still floating around the world in similar boxes.
These compromised USB-C to USB-A cables can probably be used safely if plugged into a dedicated wall charger that can’t exceed the wattage your phone demands. The problem is, two years from now, that dangerous cables can be used in a pinch and re-mixed with good cables, potentially blowing up the port on the laptop.
And don’t make the mistake of thinking that dangerous cables only came from shoddy manufacturers. Having name-brand cable won’t necessarily save you. out of five dangerous cables any 56k resistors, two came from a well known phone manufacturer, and the other came from a very popular aftermarket cable manufacturer that I still buy cables from today. Two of the cables that were wired incorrectly came from another phone manufacturer. Another USB-C Cable That Didn’t Make the Cut That Was Supplied Too Expensive high performance ssd, That’s why sticking a brand name to your chest may not always work.
Gordon Mah Ungo
How do you avoid bad cables in your collection?
The easy way to fix this is to remove the bad cables from your archive. Unfortunately there is no easy way that I know of without spending money. The easiest way I’ve found is ADUSBCIM’s Cable Checker 2, It lets you easily measure the capacity of USB-C-to-C and USB-C-to-A as well as micro and mini USB cables. The small display gives you a quick and dirty look at the cable’s resistance as well as the presence of the 56K resistor. It can also tell you if it’s wired weirdly (56K on two lines instead of one) or if it uses the wrong resistors.
Feather $65 on eBay (I haven’t found it retail in the US otherwise), this is probably the easiest way to test your cables, even though there are other, somewhat cheaper methods available.
obvious problem? It makes zero financial sense to spend $65 to test your collection of free USB-C cables. The cheaper option for most people is the one thing no one wants to do: Destroy your current pile and judge. Buy new USB-C cables Which are known to be safe and sound, for less than $65.
Should you destroy your cables?
Whether or not you should take scissors to your old USB-C to USB-A cable depends on your level of comfort with the risk. If you’ve been using the same cable for years, that’s fine. Bad USB-C cables run the risk of getting damaged when you connect a USB-C device to a computer, so if you only use them with a charger, the risk is greatly reduced. However, if a relative comes over, and unplugs that cable from the phone to your laptop to transfer some quick files, you run the risk of it getting damaged.
The last thing you want to change is your behavior on abandoned cables. If Bob flutters the bird in company and leaves a couple of USB-C to USB-A in his cubicle on his last day, leave them alone. Instead of looking at it as a “free” pair of cables, you should probably justify buy a new set of cables that you know are going to be safe.