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Does anyone else find it concerning that our new and best technology is so fragile that even the slightest fezz-up in what should be a passive signal-cable can

Does anyone else find it concerning that our new and best technology is so fragile that even the slightest fezz-up in what should be a passive signal-cable can cause our otherwise state of the art equipment to fry itself? Is reliability, durability and robustness nowhere to be found in any single spec for our new standards?

randallsquared 11y ago
USB C is not a passive signal cable.
- josteink 11y ago
  Tomay-to/tomay-to. Yes, USB C can also be used to provide power (which is also a form of signal), but again my point is that a cable like this is largely expected to be a passive component. That a crap charger can do bad things would probably surprise no one, but hooking a good charger up to a good unit shouldn't be able to fry anything, ever. Wasn't USB C supposed to make our lives easier? If we need to ensure all our USB C gadgets, cables and chargers are all not-exploding certified, in parts and in combination, I may just go back to plain old regular USB.
  - Vendan 11y ago
    Pretty sure you could make a "plain old regular" usb cable that would do similar. Maybe you should go back to RS-232? You should also beware of just about any usb device you see, as it could be a http://kukuruku.co/hub/diy/usb-killer http://kukuruku.co/hub/diy/usb-killer in disguise
  - sharpneli 11y ago
    Hooking up a good charger up to a good unit with the ground and voltage wires reversed can fry things. You can try it with your laptop. Cut the cable after the transformer, flip the ground and live wires and start it. It will get fried. Is this the fault of the specification or the person who intentionally flipped the wires? The manufacturer was the person flipping the wires in this case.
    - tobz 11y ago
      In this case, it's DC over the USB-C cable. Reverse polarity protection is 1) easy and 2) cheap. That's the most striking part to me, and I almost thought the original post was a joke... because it seems insane there wouldn't be reverse polarity detection built-in to the laptop.
      - burgeralarm 11y ago
        According to the engineer who tested the cable: "Most devices with a well-specified connector will not have any reverse bias protection in them because both it shouldn't be needed and for the technical reasons of power loss and space used. Reverse protection is usually done with diodes, the canonical "one-way valve" of electronics. Diodes have a voltage drop across them, usually 0.6V for standard and 0.4V for Schottky types. Using one of these to protect one rail means you'll have about 1W lost to heat when charging at 3A. They are also not small for the currents involved with high-speed charging, being about 7x6x2.5mm for the smallest ones I can find that can handle 3A. Devices don't usually have too much in the lines of over current protection outside of something like a polyfuse because the device will dictate the current used; if everything is okay in the device it'll set the charging rate and it only needs the most basic of protections in the case that something goes grossly wrong with the device. Sources are what really need overcurrent protection as they don't "have a say" in how much current is drawn."
        tobz 11y ago
        I mean, yeah, it makes sense. You can reasonably expect chargers/cables not to be quite this jacked up, and in turn, you save space in a space-constrained device. It's just a hard pill to swallow thinking that a stray cable could ruin my device like that. (Power dissipation aside, I did manage to find some smaller Schottky power diodes that could easily handle the current. There's also the possibility of using a MOSFET, which would turn into Rds(on) * Iavg, so something like 0.15W for Rds(on)=50mOhm, which is much more manageable. I'm just a shade tree electronics guy, so I realize there was probably enough data to make a decision to forego said protection.)
  - lostgame 11y ago
    A power cable would be a passive component. I've had several of Apple's little power charging blocks melt and burn on me. I had a CRT monitor explode when I was a kid. Just because stuff is getting smaller doesn't mean it's any more or less liable to break. You use electronics, you're taking a risk, and if you use off-brand, non-official components with other brands, well, hell, even if you're using the official brand apparently, you're playing with, well, not fire, but electricity, which is almost a cousin of fire? Heh.
  - cesarb 11y ago
    Unfortunately for you, the exact same problem can happen with plain old regular USB; in fact, this cable had only the wires from plain old regular USB. Reversing the wires on a USB 2.0 cable would have the same effect.
jonawesomegreen 11y ago
Its not a slight fezz-up really though. They reversed positive and negative on the power connections. That is a very basic mistake and one that often at least blows a fuse, if not worse.
sharpneli 11y ago
It was not a slight fezz-up. It was miswiring in a power cable. It's like electrician wiring the live pin into ground pin and then wondering why one gets electrocuted by so many devices. No specification can defend against a hostile, or sufficiently incompetent, implementer.
- pluma 11y ago
  I have actually seen a wall plug with V- and GND mixed up. Luckily nobody was injured and nothing was set on fire, but we did wonder why touching the dishwasher gave us a noticeable shock until we figured out what was wrong.
  - Dylan16807 11y ago
    Assuming you mean neutral and ground, at least those are nominally the same voltage. If you mean something else then I'm going to need more explanation of what wires are in that plug, and I'm slightly terrified that it still ran.
- greggman 11y ago
  Is that really true? (I have no idea just asking). Is there nothing you could put in the device to prevent bad inputs from damaging the internals? (for some definition of bad) Is it a question of impossibility? Or cost? Or bulk? or something else?
  - Bjartr 11y ago
    I thttp://www.fiftythree.org/etherkiller/ttp://www.fiftythree.org/etherkiller/ink http://www.fiftythree.org/etherkiller/ttp://www.fiftythree.o... it's a matter of foreseeing the potential failure modes and correctly deciding which ones are so remote as to be not worth the cost and complexity to protect against. For instance, I don't think there's a consumer device out there that wouldn't fry if connected directly to mains AC through any peripheral port at all. But that doesn't stop someone from making a cable that connects AC to USB and saying it's a fast charge cable on Amazon. That's a more extreme case than this, but only because it's more obvious what the flaw in the cable is.
lost_name 11y ago
From the review: > I directly analyzed the Surjtech cable using a Type-C breakout board and a multimeter, and it appears that they completely miswired the cable. The GND pin on the Type-A plug is tied to the Vbus pins on the Type-C plug. The Vbus pin on the Type-A plug is tied to GND on the Type-C plug. Although I haven't read the spec, following the spec is a key part making use of a standard.
heydenberk 11y ago
The issue isn't the standard, but that compliance is not regulated by the retailer, the wholesaler, the standards body or the government, which is why consumers are trying to effectively regulate it themselves.
ThePhysicist 11y ago
I would say that the Chromebook's USB ports are probably to blame as well. Shorting the +Vpp pin to GND should only result in sinking the maximum current but not in the port being damaged. Likewise, I'd expect the signal port to be protected against shorting it to GND or connecting it to a (moderately) high input voltage. The USB standard does probably not require these kind of protections, but they are nevertheless good, defensive design for any port that gets connected to a large number of unknown and potentially dangerous / badly designed devices. Btw I already destroyed some parallel, serial and USB ports when connecting them to devices I built that malfunctioned or were ill designed (during prototyping), so as a measure of safety I now often use optocouplers to galvanically isolate my circuit from the port, which can help to prevent most kinds of damage.
- cesarb 11y ago
  This was not shorting +Vpp to GND; this was putting -Vpp in the +Vpp pin. All pins are referenced to GND, which is 0V by definition, so if you put +5V in it, it's the same as subtracting 5V from the voltage in all the other pins. And since they put the 0V in +Vpp, it became -5V. Most devices aren't prepared for negative voltages.
  - ThePhysicist 11y ago
    Point taken, but I still think that the device should be protected against supplying it with a "malicious" input voltage, as there are cheap and robust components to do this. The NCP373 for example (http://www.onsemi.com/pub_link/Collateral/NCP373-D.PDF http://www.onsemi.com/pub_link/Collateral/NCP373-D.PDF) protects against voltages between -30 to 30 V and is designed exactly with the "faulty USB cable" use case in mind, and the low-volume cost is just 50 cents (large-volume cost is probably much lower). So I think there really is no excuse for letting a faulty 5 $ USB cable destroy your 1000 - 2000 $ device, even if it supplies an input voltage of the wrong polarity.
pyre 11y ago
This isn't the first time stuff like this has happened. I had a Sansa Fuze MP3 player (from SanDisk) a while back. It used the exact same connector as the iPod. The only difference is two of the wires were swapped. One of them being PWR, so if you used an Apple cord, you would fry your player.
mikeash 11y ago
I agree that these ports should be robust against abuse, but reversing polarity on a DC power cable is far from a "slight" screwup.
27182818284 11y ago
Completely, no, but you can certainly safeguard. The One Laptop Per Child machines could take a reverse of positive and negative leads directly from a car battery and still be okay. The idea being that some poor kid somewhere was going to mess that up one day while trying to give it power. (Or rather I should say an EE prof told me this. I have personally not tried to electrocute any poor OLPCs)

randallsquared 11y ago

USB C is not a passive signal cable.

josteink 11y ago
Tomay-to/tomay-to. Yes, USB C can also be used to provide power (which is also a form of signal), but again my point is that a cable like this is largely expected to be a passive component. That a crap charger can do bad things would probably surprise no one, but hooking a good charger up to a good unit shouldn't be able to fry anything, ever. Wasn't USB C supposed to make our lives easier? If we need to ensure all our USB C gadgets, cables and chargers are all not-exploding certified, in parts and in combination, I may just go back to plain old regular USB.
- Vendan 11y ago
  Pretty sure you could make a "plain old regular" usb cable that would do similar. Maybe you should go back to RS-232? You should also beware of just about any usb device you see, as it could be a http://kukuruku.co/hub/diy/usb-killer http://kukuruku.co/hub/diy/usb-killer in disguise
- sharpneli 11y ago
  Hooking up a good charger up to a good unit with the ground and voltage wires reversed can fry things. You can try it with your laptop. Cut the cable after the transformer, flip the ground and live wires and start it. It will get fried. Is this the fault of the specification or the person who intentionally flipped the wires? The manufacturer was the person flipping the wires in this case.
  - tobz 11y ago
    In this case, it's DC over the USB-C cable. Reverse polarity protection is 1) easy and 2) cheap. That's the most striking part to me, and I almost thought the original post was a joke... because it seems insane there wouldn't be reverse polarity detection built-in to the laptop.
    - burgeralarm 11y ago
      According to the engineer who tested the cable: "Most devices with a well-specified connector will not have any reverse bias protection in them because both it shouldn't be needed and for the technical reasons of power loss and space used. Reverse protection is usually done with diodes, the canonical "one-way valve" of electronics. Diodes have a voltage drop across them, usually 0.6V for standard and 0.4V for Schottky types. Using one of these to protect one rail means you'll have about 1W lost to heat when charging at 3A. They are also not small for the currents involved with high-speed charging, being about 7x6x2.5mm for the smallest ones I can find that can handle 3A. Devices don't usually have too much in the lines of over current protection outside of something like a polyfuse because the device will dictate the current used; if everything is okay in the device it'll set the charging rate and it only needs the most basic of protections in the case that something goes grossly wrong with the device. Sources are what really need overcurrent protection as they don't "have a say" in how much current is drawn."
      - tobz 11y ago
        I mean, yeah, it makes sense. You can reasonably expect chargers/cables not to be quite this jacked up, and in turn, you save space in a space-constrained device. It's just a hard pill to swallow thinking that a stray cable could ruin my device like that. (Power dissipation aside, I did manage to find some smaller Schottky power diodes that could easily handle the current. There's also the possibility of using a MOSFET, which would turn into Rds(on) * Iavg, so something like 0.15W for Rds(on)=50mOhm, which is much more manageable. I'm just a shade tree electronics guy, so I realize there was probably enough data to make a decision to forego said protection.)
- lostgame 11y ago
  A power cable would be a passive component. I've had several of Apple's little power charging blocks melt and burn on me. I had a CRT monitor explode when I was a kid. Just because stuff is getting smaller doesn't mean it's any more or less liable to break. You use electronics, you're taking a risk, and if you use off-brand, non-official components with other brands, well, hell, even if you're using the official brand apparently, you're playing with, well, not fire, but electricity, which is almost a cousin of fire? Heh.
- cesarb 11y ago
  Unfortunately for you, the exact same problem can happen with plain old regular USB; in fact, this cable had only the wires from plain old regular USB. Reversing the wires on a USB 2.0 cable would have the same effect.

jonawesomegreen 11y ago

Its not a slight fezz-up really though. They reversed positive and negative on the power connections. That is a very basic mistake and one that often at least blows a fuse, if not worse.

sharpneli 11y ago

It was not a slight fezz-up. It was miswiring in a power cable. It's like electrician wiring the live pin into ground pin and then wondering why one gets electrocuted by so many devices. No specification can defend against a hostile, or sufficiently incompetent, implementer.

pluma 11y ago
I have actually seen a wall plug with V- and GND mixed up. Luckily nobody was injured and nothing was set on fire, but we did wonder why touching the dishwasher gave us a noticeable shock until we figured out what was wrong.
- Dylan16807 11y ago
  Assuming you mean neutral and ground, at least those are nominally the same voltage. If you mean something else then I'm going to need more explanation of what wires are in that plug, and I'm slightly terrified that it still ran.
greggman 11y ago
Is that really true? (I have no idea just asking). Is there nothing you could put in the device to prevent bad inputs from damaging the internals? (for some definition of bad) Is it a question of impossibility? Or cost? Or bulk? or something else?
- Bjartr 11y ago
  I thttp://www.fiftythree.org/etherkiller/ttp://www.fiftythree.org/etherkiller/ink http://www.fiftythree.org/etherkiller/ttp://www.fiftythree.o... it's a matter of foreseeing the potential failure modes and correctly deciding which ones are so remote as to be not worth the cost and complexity to protect against. For instance, I don't think there's a consumer device out there that wouldn't fry if connected directly to mains AC through any peripheral port at all. But that doesn't stop someone from making a cable that connects AC to USB and saying it's a fast charge cable on Amazon. That's a more extreme case than this, but only because it's more obvious what the flaw in the cable is.

lost_name 11y ago

From the review: > I directly analyzed the Surjtech cable using a Type-C breakout board and a multimeter, and it appears that they completely miswired the cable. The GND pin on the Type-A plug is tied to the Vbus pins on the Type-C plug. The Vbus pin on the Type-A plug is tied to GND on the Type-C plug. Although I haven't read the spec, following the spec is a key part making use of a standard.

heydenberk 11y ago

The issue isn't the standard, but that compliance is not regulated by the retailer, the wholesaler, the standards body or the government, which is why consumers are trying to effectively regulate it themselves.

ThePhysicist 11y ago

I would say that the Chromebook's USB ports are probably to blame as well. Shorting the +Vpp pin to GND should only result in sinking the maximum current but not in the port being damaged. Likewise, I'd expect the signal port to be protected against shorting it to GND or connecting it to a (moderately) high input voltage. The USB standard does probably not require these kind of protections, but they are nevertheless good, defensive design for any port that gets connected to a large number of unknown and potentially dangerous / badly designed devices. Btw I already destroyed some parallel, serial and USB ports when connecting them to devices I built that malfunctioned or were ill designed (during prototyping), so as a measure of safety I now often use optocouplers to galvanically isolate my circuit from the port, which can help to prevent most kinds of damage.

cesarb 11y ago
This was not shorting +Vpp to GND; this was putting -Vpp in the +Vpp pin. All pins are referenced to GND, which is 0V by definition, so if you put +5V in it, it's the same as subtracting 5V from the voltage in all the other pins. And since they put the 0V in +Vpp, it became -5V. Most devices aren't prepared for negative voltages.
- ThePhysicist 11y ago
  Point taken, but I still think that the device should be protected against supplying it with a "malicious" input voltage, as there are cheap and robust components to do this. The NCP373 for example (http://www.onsemi.com/pub_link/Collateral/NCP373-D.PDF http://www.onsemi.com/pub_link/Collateral/NCP373-D.PDF) protects against voltages between -30 to 30 V and is designed exactly with the "faulty USB cable" use case in mind, and the low-volume cost is just 50 cents (large-volume cost is probably much lower). So I think there really is no excuse for letting a faulty 5 $ USB cable destroy your 1000 - 2000 $ device, even if it supplies an input voltage of the wrong polarity.

pyre 11y ago

This isn't the first time stuff like this has happened. I had a Sansa Fuze MP3 player (from SanDisk) a while back. It used the exact same connector as the iPod. The only difference is two of the wires were swapped. One of them being PWR, so if you used an Apple cord, you would fry your player.

mikeash 11y ago

I agree that these ports should be robust against abuse, but reversing polarity on a DC power cable is far from a "slight" screwup.

27182818284 11y ago

Completely, no, but you can certainly safeguard. The One Laptop Per Child machines could take a reverse of positive and negative leads directly from a car battery and still be okay. The idea being that some poor kid somewhere was going to mess that up one day while trying to give it power. (Or rather I should say an EE prof told me this. I have personally not tried to electrocute any poor OLPCs)