The USB-C Connectors You Never Knew You Wanted To Avoid

On the left, four through-hole USB-C connectors laid out on a purple cutting mat. On the right, a teardown picture shows that there's neither resistors nor CC connections inside such a connector, resulting in consequences described in the article.

On Tech Twitter, some people are known for Their Thing – for example, [A13 (@sad_electronics)], (when they’re not busy designing electronics), searches the net to find outstanding parts to marvel at. A good portion of the parts that they find are outstanding for all the wrong reasons. Today, that’s a through-hole two-pin USB Type-C socket. Observing the cheap tech we get from China (or the UK!), you might conclude that two 5.1K pulldown resistors are very hard to add to a product – this socket makes it literally impossible.

We’ve seen two-pin THT MicroUSB sockets before, sometimes used for hobbyist kits. This one, however, goes against the main requirement of Type-C connectors – sink (Type-C-powered) devices having pulldowns on CC pins, and source devices (PSUs and host ports) having pull up resistors to VBUS. As disassembly shows, this connector has neither of these nor the capability for you to add anything, as the CC pins are physically not present. If you use this port to make a USB-C-powered device, a Type-C-compliant PSU will not give it power. If you try to make a Type-C PSU with it, a compliant device shall (rightfully!) refuse to charge from it. The only thing this port is good for is when a device using it is bundled with a USB-A to USB-C cable – actively setting back whatever progress Type-C connectors managed to make.

As much as USB Type-C basics are straightforward, manufacturers get it wrong on the regular – back in 2016, a wrong cable could kill your $1.5k MacBook. Nowadays, we might only need to mod a device with a pair of 5.1K resistors every now and then. We can only hope that the new EU laws will force devices to get it right and stop ruining the convenience for everyone, so we can finally enjoy what was promised to us. Hackers have been making more and more devices with USB-C ports, and even retrofitting iPhones here and there. If you wanted to get into mischief territory and abuse the extended capabilities of new tech, you could even make a device that enumerates in different ways if you flip the cable, or make a “BGA on an FPC” dongle that is fully hidden inside a Type-C cable end!

24 thoughts on “The USB-C Connectors You Never Knew You Wanted To Avoid

  1. I still do not own a single USB C to C cable.

    I had one for hot minute, but as soon as my Oculus Quest arrived with the LCD shards rattling around I returned it.

    The day will come, but I still don’t get the allure of one socket for everything. Sure it sounds nice, but you still need a special cable for every other device. Or a dongle to make DisplayPort or USB A

    1. I can take my laptop and plug a single USB-C cable in (either way up!) and suddenly the laptop is charging, displaying on a large 4k screen, proper mouse, full-sized keyboard and decent speakers. Unplug, and carry on exactly where I left off, except smaller. Take the laptop to the workshop where I have a similar setup and it’s a full-blown workstation again. Super convenient, that’s the allure for me.

      1. I thought this would be the dream as well, but I get flickering during scrolling when I use my Dell machine (stock shipped Linux distro) and my DELL USB-C monitor setup.
        Moreover, sometimes the machine just crashes when you disconnect the USB-C cable.

        1. I have Dell kit too – two Dell XPS 13s, one runs kubuntu 18.04 and the other openSuse, both work as described but I did have a few issues when 18.04 first came out, fixed ages ago by updates. My workshop setup uses a separate Dell USB-C dock which I originally had to upgrade the firmware of (a couple of years ago now); the other setup uses a recent Dell monitor which “just worked”.

    2. the (cheap!) cables with power trigger boards allow a lot of clutter reduction…I have a 65W USB-C powerbrick and a 65W-capable power bank, with these I can power:
      – a TS100 iron
      – an unmodded Dell laptop
      – a modded x230 laptop
      – any USB device…
      The brick will charge the power bank in under 1.5 hours (both get worringly warm though) and it fits into my hand, the powerbank is a little chunkier given the 60Wh capacity and 65W power capability, but it’s still small and portable. If they ever die, I can buy a compatible one for years to come, no more single purpose PSUs with unique connectors.

  2. (Or the UK!)… What? who? a UK manufacturing company is competing head to head with our Chinese cousins, you cannot blame them for wanting to reduce the cost by 50% on the parts that go into each one. Who let accountant drive! 😁

    1. Yeah, bit lost on the UK reference here – from the pic and looking at LCSC, they appear to be the “Korean Hroparts” ones, which are nothing to do with the UK. And if they’re rubbish, wouldn’t it have been helpful of “A13” to say what parts they were? LCSC sell a lot of stuff…

        1. Which is an honest mistake versus outright specification fraud and intentionally too-cheap design resulting in unsafe products that could burn your home down and potentially kill you and your family. But, after all, it’s a country that sells nutrient free baby formula to its own people along with all kinds of other scandals that never reach the international news. Business in China, unless constrained by on-site Western ethics guiding QC, is totally unethical and that is a cultural thing.

  3. I very much love USB-C. It’s so handy being able to just use the same cables and chargers and powerbanks for everything, as long as you only need 100W or less of power.

    I got my laptop a USB-C adapter for its odd 4mm barrel-socket, so I can charge it up from the same source I charge up my earbuds, my phone, my tablet, my mouse and so on.

    I also turned an old laptop-display into a portable display: the control PCB for it only has a barrel-socket for 12V power, but I added a USB-C 12V trigger in parallel, so I can use e.g. my 18W or 65W powerbank to run it, or hook it up to a USB-charger or use a 12V PSU with a male barrel-jack on the output, all depending on what’s most convenient to me at the moment — if e.g. something goes wonky enough with one of my servers that it needs some hands-on time, I can just grab the portable display, a powerbank and a wireless keyboard and hammer away at it.

  4. I refuse to use USB C in any of my projects. Too small, too flimsy, too complicated, too failure prone. On my last two projects that needed USB, I went out of my way to use a USB 1 \ 2 type B (yes, full size type B) jack. I’ve never seen one fail. Micro B and C, on the other hand…

    1. I feel the same. Just love those classic connectors. The B type is still being used for a reason.

      Printers, scanners, external USB HDDs, EEPROM programmers.. All the valuable stuff uses the bigger connectors.

      The professional stuff uses DB25, even, which has screws for secure mounting.

      That’s why I’m so glad that the “old” USB 3.0 specification still introduced an updated B connector and made it backwards-compatible, too!

      I’m also glad that NEC/Renesas still made XP compatible drivers for their USB 3.0 chips back in ~2010.
      Many development tools are 32-Bit only, also because of driver signing issues (required on 64-Bit Windows).

      And USB 3.0 A-type or B-Type ports can provide enough current for legacy devices in a stable manner.
      The forementioned EEPROM programmers can benefit from this, too.

    2. ” Too small, too flimsy, too complicated, ” What! Its larger than a micro usb. Flimsy…. It’s used on every modern device out there. If it were flimsy it wouldn’t be used. As far as complicated goes. Not sure what could possibly be so complicated about a connector.

      1. @Mike: Micro-USB had the same problem. I’ve gone through a myriad of cables and at least a couple of connectors on each phone, and I don’t even have kids around. My friends with kids have to stockpile cables.

        Honestly, I’d like mini-USB cables for charging things at the absolute smallest! Some of my stuff has these, and I’ve only ever had to buy new cables because I lost the old ones, not because I wore the connectors out.

        Unfortunately the pursuit of thinner phones has demanded thinner cables, but nobody has bothered to compliment this with stronger materials because of the race to the bottom on cost.

    3. I designed a gadget for elderly (poor eyesight) that was charged daily. Over five years and tens of thousands in the field, and the usb jack failures reported could be counted on one hand.

      That makes me ask… Are you are specifying the wrong jack, buying cheap junk, or are you abusing your devices? Because if thousands of half blind senior citizens can make them last, it makes me believe more is going on.

  5. I love the USB HUB HAT for my Pi Zero W. Only one problem… the dual micro USB connector board is wired wrong! I’ve bought several, they are all wired wrong. The way they are wired the HUB HAT will not work. It’s a very simple fix, the VBUS_Sense line needs to be pulled low. If it’s not pulled low the PI will not recognize the device as a peripheral. All you need to do is add a short between VBUS_Sense and ground. Another example of cheap stuff wired wrong!

  6. im still not sold on usb-c. they intend it as the ‘one connector to replace them all’. but they fail to realize the reason we ended up with so many usb connector standards in the first place is that a one size fits all connector its really just not possible. that a connector that works great on a phone might not be suited to say industrial applications. my 3d printer for example vibrated its usb-micro connector right off the board. this is also the reasons 2d printers use the monstrous b-connector. what is needed is an upscale c that is maybe the size and depth of the a. two connectors to rule them all is more reasonable.

    1. ” my 3d printer for example vibrated its usb-micro connector right off the board. this is also the reasons 2d printers use the monstrous b-connector.” neither of these are reasons why. The first issue is two fold. If your 3D printer is vibrating that bad to snap a connector off you have bigger issues. Secondly, There are many different types of USB C connectors out there. Some with more case legs to be soldered to the board more securely.
      This is NOT the reason why they use the “monstrous b-connector” for 2 d printers. It’s because of cost and nothing else.

      1. Why would the far larger B connector be cheaper than the ubiquitous micro USB connector that’s churned out in unfathomable numbers? It doesn’t make any sense, and doesn’t pass a quick sniff test on AliExpress

    2. I like “two connectors to rule them all.”

      I’ve fully converted to USB-C everywhere I can, and default to it for new designs. That said, I’m still using USB Type B on test fixtures and other critical or industrial-adjacent equipment. It’s just a different level of chonk.

      If we had an upscaled industrial version of USB-C, I could finally leave Type B behind. Something on the scale of a DisplayPort connector, with a positive lock. Require all the cables to support the new 240W charging profile for good measure. If you need more power than that, you want an IEC plug anyway.

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