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Bad USB-C cable destroys laptop

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Re: Bad USB-C cable destroys laptop

#31

Post by mikeash »

krapht wrote: post #28
andrey-g wrote: post #20

Earlier quoted context omitted.

I constantly have Vdd shorts due to ground loops when measuring stuff. But a more frequent case is worn out cables (every lightning cable I've owned has eventually broke). Its not rare enough of a failure mode to ignore.

Yes, and that's why the USB spec puts the burden of protecting against electrical shorts on the controller. The device side shouldn't have to worry about trying to shunt 100 Watts of power somewhere. I mean this kind of protection is way beyond typical ESD protection due to the power involved. It would add a lot of cost to do this, maybe even a dollar or two in raw material.

If you stop the current from flowing, you don't have to shunt any power anywhere.

You'd have to open the circuit in the face of 5V of potential hooked up backwards, not really a tall order.

Re: Bad USB-C cable destroys laptop

#33

Post by bsimpson »

AdmiralAsshat wrote: post #12

HN has previously had a story on the author, a Google engineer who tests USB-C cables on Amazon to make sure they're spec-compliant. He does some amazing work: https://news.ycombinator.com/item?id=10508494 I don't have any devices right now that use USB-C, but whenever I see a deal pop up for one, I usually check the Amazon listing to see if this guy has reviewed/certified the cable yet. I recommend others do the sam…

I bought one of these recently, based on Benson's endorsement, for my Nexus 5X:

http://smile.amazon.com/dp/B018F8BGLA

It's worth noting that the Nexus 5x doesn't do USB 3.1, so even if you get a fancy Super Speed cable like this one, you are still suck with slow charging from your computer's USB A port.

Re: Bad USB-C cable destroys laptop

#34

Post by tomswartz07 »

guelo wrote: post #22

USB-C seems like a really bad standard if the cable can destroy expensive electronics. EDIT: Even if the cable is wired and built correctly (which is apparently difficult for manufacturers to get right), cables fray and tear all the time. I foresee a lot of dead electronics upcoming.

It's not the standard that's bad, it's the actual wiring of it.

That's akin to saying:

The US power grid is a bad standard because I wired up my house wrong and it burned down.

Re: Bad USB-C cable destroys laptop

#35

Post by bsimpson »

ThinkBeat wrote: post #32

He is brave to do his testing on such a nice computer. I hope he somehow gets this covered. Amazon should pay him for his work.

He's a Google employee, presumably using corporate hardware to advance the USB C ecosystem that the Pixel line is shepherding. I'd be shocked if Google didn't let him replace it.

Re: Bad USB-C cable destroys laptop

#37

Post by symmetricsaurus »

Killed a laptop when plugging in my phone (with the old 30 pin connector). Turns out a bit of foil from a wrapper had become stuck in the slot on the phone.

Since this was in the bad old day the laptop was fixable for under $200 so it wasn't too bad.

Still, makes sense to keep an eye on what you plug into your computer.

Re: Bad USB-C cable destroys laptop

#38

Post by cybrjoe »

tomswartz07 wrote: post #34
guelo wrote: post #22

USB-C seems like a really bad standard if the cable can destroy expensive electronics. EDIT: Even if the cable is wired and built correctly (which is apparently difficult for manufacturers to get right), cables fray and tear all the time. I foresee a lot of dead electronics upcoming.

It's not the standard that's bad, it's the actual wiring of it. That's akin to saying: The US power grid is a bad standard because I wired up my house wrong and it burned down.

It seems more like saying:

The US power grid is a bad standard because I wired up my house wrong and it burned the power station down.

Re: Bad USB-C cable destroys laptop

#39

Post by paulmd »

earlz wrote: post #10

TL;DR; USB-C cable had GND tied to Vbus and Vbus tied to GND (opposite as it should be) Honestly, I'm surprised that this isn't something that thelaptop and other such USB adapters aren't equipped to deal with. This is only slightly worse in my book than a USB adapter being fried from shorting the Vbus and GND pins together

Electrical faults are just a fact of life. Wires fray, cables get tugged, or are miswired from the factory. And you just know that sooner or later some genius is gonna jam a butter knife in there for the hell of it.

The basic USB spec requires that all ports be protected with a small self-resetting polyfuse for exactly this reason. I don't know if the Type-C or USB 3.1 specs includes something similar - I would assume so but perhaps the additional current capabilities made that infeasible.

http://elinux.org/Polyfuses_explained

A standard USB polyfuse usually resets pretty fast (as soon as it cools down) but they could take up to a few days. It's also possible the manufacturer cheaped out and didn't include a polyfuse, of course.

Re: Bad USB-C cable destroys laptop

#40

Post by kentonv »

hartator wrote: post #2

My biggest surprise here is there is still people using Google+.

Honestly G+ is amazing for technical discussion. Examples from my feed:

https://plus.google.com/+KentonVarda/posts/cFsgVBuXinb

https://plus.google.com/+KentonVarda/posts/JDwHfAiLGNQ

At least in my experience, FB and Twitter simply don't produce anything like that.

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