Question Can I connect USB-A devices directly to a USB-C port on my laptop?

[TrevorLivesOn]

TLDR: Why won't my HDD enclosure connect to my Macbook Pro with a USB-A to USB-C cable?

Hi folks. I have a couple of peripherals that connect to a computer from a USB-A socket. They include a hard drive enclosure and a laptop cooling stand. On my old Macbook Pro which had USB-A ports, I used a USB-A to USB-A (male to male) cable to connect these devices and all seemed fine.

Now that I have a newer laptop (MBP 14" 2021) with USB-C (Thunderbolt 4) ports, I have been unable to find a USB cable to connect these devices directly. I tried a couple of different USB-A to USB-C cables that had come with my phone and tablet, but nothing happens - as if no power is delivered to the HDD enclosure or the cooling stand, no sign of life. I recently bought a new cable in the hope that it would be correctly specified for the job:

USB 3.2 Type C Male to Type A Full Feature Gen2 Cable 10Gb 3 Amp 0.5m

USB3.2 Gen 2 brings many improvements to the previous standard USB3.0 (Gen.1). The most noticeable is the new Type-C connector which is much smaller than the previous standard connectors it is also reversible... [see below for full description]

www.kenable.co.uk

... but as you may guess by now, it also isn't connecting. I don't think the cable is a dud - it does charge my Android phone when plugged into a USB-A outlet.

I am still able to connect these devices to my new laptop by using my old USB-A to USB-A (male to male) cable via a hub (a bus-powered one), or a basic USB-C male to USB-A female adapter:

USB 3.1 Type A Female to Type C Male Gen 1 Cable 5GBps 3 Amp 15cm

USB3.0 (Gen.1). The most noticeable is the new Type-C connector which is much smaller and reversible. The Type-C connector is backwards compatible and can be used with USB3... [see below for full description]

www.kenable.co.uk

...so it's only a mild inconvenience. What bothers me more is that I am probably not understanding something about how USB connections are supposed to work, so I'd be grateful if anyone can enlighten me. Or, if it IS supposed to work this way, I'd be grateful if anyone can recommend the correct cable for the job.

Many thanks.

 

[lvt]

Is the laptop's port USB-C or Thunderbolt?

 

[TrevorLivesOn]

Is the laptop's port USB-C or Thunderbolt?

Thanks for the reply - according to Apple, the ports supports both USB 4 and Thunderbolt 4.

In full (from the specs page) - Three Thunderbolt 4 (USB-C) ports with support for:
- Charging
- DisplayPort
- Thunderbolt 4 (up to 40Gb/s)
- USB 4 (up to 40Gb/s)


I've been wondering if my USB-A to USB-C cables have an 'intended direction' or something. Perhaps they are intended to provide power from the USB-A end to a device on the USB-C end (hence they work for charging my phone) but the cables don't allow the right communication/handshake to provide power from the USB-C end to a device on the USB-A end?

 

[lvt]

Do you have any other USB device that actually works with your Thunderbolt port using the cable you mentioned above?

 

[TrevorLivesOn]

Do you have any other USB device that actually works with your Thunderbolt port using the cable you mentioned above?

No - I only have 3 devices with USB-A sockets (two similar HDD enclosures and a laptop cooler/stand but I haven't got any of them working with this type of cable. I've swapped between 3 different USB-A to USB-C cables so hopefully that rules out a dud cable. Also tried each of the USB-C ports on the laptop but no difference.

These cables do actually work with the laptop's USB-C ports when connected to a USB-A power outlet - they then charge the laptop. But the laptop doesn't seem to send power out when using those cables.

Perhaps unrelated but I also have a USB-C to USB-C cable and that cable works in both directions - it can charge up the laptop when connected to a USB-C power outlet, and it can also charge up my phone when connected between laptop and phone.

 

[lvt]

So you can't be sure that the ports are fully working, right?

 

[TrevorLivesOn]

So you can't be sure that the ports are fully working, right?

It seems to me that the ports are working, because I can connect my HDD enclosure to those ports using an adapter or hub in between.

The simplest solution I have at the moment is to use a USB-C male to USB-A female cable plugged into my laptop, and then use a USB-A to USB-A cable from there to the HDD enclosure, and it works. I can pretend that it's just 1 cable if I ignore the join in the middle, after all it has a USB-C plug at one end and a USB-A plug at the other.

Using a USB hub also works, even an unpowered one - similarly I then take a USB-A to USB-A cable from the hub to the HDD enclosure or cooling stand and they work.

Is this a question for Apple customer service do you think? The whole situation is not the end of the world, really I just want to understand how these things work.

 

[lvt]

So the problem could be the cable, you may need to find the right Thunderbolt <=> USB-A cable.

Alternatively, you can replace the HDD enclosure with other having USB-C port for better compatibility.