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USB Type-C cable so bad it fries Google engineer’s Chromebook Pixel

Benson Leung, the Type-C cable testing vigilante, has finally met his match.

USB Type-C cable so bad it fries Google engineer’s Chromebook Pixel

Benson Leung, the Google engineer who moonlights as a tester of dodgy USB Type-C cables, has sadly performed his last act of tech vigilantism—at least for now. When testing a Surjtech 3M USB A-to-C cable, the cable was so bad that it fried his Chromebook Pixel laptop and two USB PD (power delivery) analysers.

At the time of publishing, it looks like the Surjtech cable has already been removed from Amazon, but Leung's review lives on. Basically, as soon as the cable was plugged in and turned on, it completely fried the Vbus line on the Twinkie USB PD analyser. "This is permanent damage. I tried resetting the Twinkie analyzer and having the firmware reflashed, but it continues to exhibit this failure," Leung wrote.

Not only did the cable kill the analyser, though, but it also fried both USB Type-C ports on Leung's Chromebook Pixel: "Neither would charge or act as a host when I plugged in a USB device such as an ethernet adapter."

Upon further analysis, Leung found that the cable had killed the Chromebook's embedded controller, a chip that manages tasks such as keyboard initialisation, USB charging, and reading temperature sensors. Unfortunately this meant that the laptop could no longer boot up: because Chrome OS's Verified Boot tech could no longer verify the embedded controller, it would only boot into recovery mode. (As far as Verified Boot is concerned, the controller might've been compromised in some way.)

To find out what sort of devilry had fried his gear, Leung then analysed the cable with a breakout board and a multimeter. What he found was really quite shocking: "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."

And that's not all! Later, after posting about his woes on Google+, Leung found a battery of further issues:

...
2) 10 kΩ resistor instead of 56 kΩ resistor used.
3) resistor hooked up as a Pull-down instead of a pull-up
4) Wire is COMPLETELY missing SuperSpeed wires. It is NOT actually a USB 3.1 cable, even though it has a blue connector on the A side and SuperSpeed logos.

If the miswiring was the only issue with the cable then Surjtech could plausibly defend this as a one-off manufacturing fault. Considering the three other compounding issues, though, it sounds like Surjtech just doesn't know how to make a USB cable.

And finally, for a few more laughs, I dug up the original Surjtech cable product page from the Google cache. Check out this paragraph:

Well-made with High Quality: Best quality cable in the market - aluminium alloy connector & high density braided nylon net for long-term use The combination of sturdy construction with a flexible jacket and USB 3.1 Type C connector with molded strain relief provides a cable with reliable performance and long life.

If only Surjtech had put as much thought into the actual electronics as the moulded strain relief...

Leung says he will be "contacting Surjtech directly," presumably with the hope of getting a new Pixel laptop so that he can continue his USB Type-C cable reviews.

Channel Ars Technica