Hacker News Reader

Comment by jmbwell | Hacker News Reader

3) The most fragile part (the wafer in the center of the receptacle) is on the expensive-to-repair device, while the least fragile part is on the cheap-to-replace cable. HDMI makes this same mistake. With USB-A, at least the plastic part on the device is relatively robust, and with Lightning, both plug and socket were rather robust (albeit prone to debris incursion). With older pin-type connectors like VGA and DVI, the fragile pins are completely on the replaceable cable.

View on HN

Im not sure this is true, the part in the cable is just tiny pins and far more vulnerable than the wafer. For years now I've dug woodchips and other junk out of my phones usb-c socket with paperclips and never came close to damage. It seems sufficiently recessed to prevent all but the most aggressive attack.

Edit: in fact, trying now it seems to be perfectly recessed that I can't even push on it from an angle with the connector, it has to go straight in a bit before it even touches, on any of my devices

I mean, I'm referring to things I've had to deal with. Failure isn't obvious until the user complains of random disconnects, and then you find that although everything looks fine from the outside, you can wiggle the wafer inside like a loose tooth. The plastic of the wafer has cracked and is being held in place only by the metal in the contacts.

I'll grant that it's robust in that it continues to work more than I'd expect, for example continuing to charge the laptop but not reliable for the external display. And once connected, sure it's secure.

I suspect it's not the cable mating that causes the failure, but other foreign objects… keys in the bag or something… that manage to dislodge it. And some laptops have more play in the connector than others, which I think allows the connector on the cable end to hit the wafer with an angle of attack sufficient to dislodge it. Some of my users handle heavy bulk materials all day and are anything but gentle with computers.

In any case, I'm sure the designers considered this, and far be it from me to second-guess their compromises. It is what it is. But if the port has failure modes, this is one of them.

It's almost as if the designers have considered this potential failure mode for devices that often get dropped even while plugged into a charger :)

I can emphasize with many of the gripes people have with USB-C cables and supported modes being confusing, but the port is really, really well thought out: Make the cable the part that fails more easily [1]; make it so that the plug only minimally acts as a lever while partially or fully plugged in; cover the pins on the plug (because otherwise people will inevitably touch them, and these cables can carry up to 48 V of voltage).

[1] That part has actually worked well for everything but my Yubikey :( USB-A and an adapter it is for the next one.

A significant issue probably affecting your Yubikey is that there are very few male USB-C plugs available. The ones that do exist are mostly designed for USB-C cables, which uses a tiny 0.8mm thick "paddle card" fully embedded in the plastic cover.

Alternatively, there are "brick nogging" connectors which stand up straight from the PCB and are therefore unusable for a Yubikey, or "sink board" ones which require a custom jig for assembly.

Meanwhile with USB-A you don't even need a male connector at all - just have a bit of your PCB stuck out in a vaguely USB-A-looking shape and it'll work just fine.

> The most fragile part (the wafer in the center of the receptacle) is on the expensive-to-repair device, while the least fragile part is on the cheap-to-replace cable.

Why do you think that the wafer is the most fragile part?

One might argue that the latch mechanism would be the part most exposed to wear and tear due to mechanical stress incurred by plugging and removing. Those side latches are located in the plug, not in the receptacle.

See also figure 3-14 in the USB-C spec [1].

[1]: https://www.usb.org/sites/default/files/USB%20Type-C%20Spec%...

Personally my last two phones have had this. It starts slowly - the cables occasionally don't work, then some cables won't work at all, then no cables work without 2 minutes of gentle manipulation, eventually it becomes almost impossible to charge. You waste so much time on this before it gets so bad that you can't live another day with the phone.

I haven't seen a USB-C cable that has wore out.

I've had this happen about three times now, but every time the actual problem is pocket lint inside the connector. After I clean it out it is back to working like new. It's not always obvious that it's lint until you start scraping back there since it gets jammed pretty hard when plugging in the cable.

Doesn't seem like one would preclude the other.

I guess I'll have to take a video next time I see it.

I was told this exact opposite argument about Lightning being worse than USB-C. The line of reasoning was that the springy part breaks and in USB-C the springy bit is in the cable, while in Lightning the pins are sturdy.

It was a specific design goal of USB-C to put the fragile part on the cable, not on the device.

For people who are not versed in mechanical connector design it might look like the fragile part is that center wafer.

USB-A is massive compared to USB-C, that's why it's so robust, thick plastic, thick metal, wide connector lanes.

If USB-C is fragile, is just because it's so small, you can easily break it with not so much pressure.

The worst connector for that problem is those ----ing antenna leads your laptop has for an M2 wifi card.

I broke the ring on a M.2 Wi-Fi card, but installed the cable onto it anyway. I think the part I bent off will probably rip off and get stuck in the cable the next time I take the connector off the card. Here's hoping I'll never have to do that...

I believe those are MCX. My Shure SE215 IEMs (earphones) use the same connector.

Those connectors are good for one connection and no disconnections.

My mother bent the "least fragile part" on at least a dozen wires meanwhile the port itself kept working.

Reply on news.ycombinator.com