Dodgy $10 USB Type-C cable fries moonlighting engineer’s $1,000 laptop

Benson Leung, a Google engineer discovered the fright of using dodgy gadgets when a spurious USB Type-C cable fired his $1000 Chromebook Pixel. Leung who also moonlights as a tester for USB Type-C cables finally found his match when he was testing a Surjtech 3M USB A-to-C cable which is available on Amazon for $9.98.

The spurious cable not only fried his Chromebook Pixel laptop but also two USB PD (power delivery) analysers.

Leung says that as soon as he plugged in the cable and turned it 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.”

Leung did some detective work and found that the dodgy cable had destroyed his Chromebook’s embedded controller, a chip that manages tasks such as keyboard initialisation, USB charging, and reading temperature sensors.

Curious at the incident, Leung decided to inspect the dodgy cable. Leung 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.”

Heung decided to warn other buyers of the product and made a post on Google+

2) 10 k? resistor instead of 56 k? 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.

Immediately after Leung’s review, Amazon decided to play it safe and removed Surjtech USB Type-C cable but the Google cache of the webpage with Leung’s review lives on.

Ars’  dug out this paragraph from the product description page of Surjtech.

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.

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