Google software engineer Benson Leung has been testing and reviewing the various third-party USB Type C cables that are sold on Amazon and other vendors for the past few months. With a list of more thanr 100 posts shared on his Google + account, Leung has been able to uncover some options that are worthy of purchasing.
However, each time he connects a new cable into his laptop, he risks the possibility of some damaging consequences. And now his mission to make sure these USB-C cables are safe and compliant has momentarily come to an end.
During his testing of a Surjtech 3M USB A-to-C cable, Leung soon found just how bad this option was after it fried his Chromebook Pixel 2 laptop, as well as two USB PD Sniffer devices.
In an Amazon customer review, Leung revealed that he plugged the 3M USB A-to-C cable into the "twinkie," the USB PD (power delivery) sniffer device as a pass through, as well as into his Chromebook Pixel 2.
"Twinkie's current and voltage measurement command (tw vbus) failed immediately after plugging this cable with the adapter into it. This is permanent damage," he wrote in the review. "I tried resetting the Twinkie analyzer and having the firmware reflashed, but it continues to exhibit this failure. It is no longer able to use its voltage and current measurement capability on the Vbus line."
As for his laptop, Leung reported that both USB Type-C ports stopped responding immediately.
"Neither would charge or act as a host when I plugged in a USB device such as an Ethernet adapter," he wrote. "Upon rebooting my Pixel, the system came up in recovery mode because it could not verify the Embedded Controller on the system. No amount of software recovery could revive the EC. Upon closer analysis, serious damage has been done to components related to charging and managing the USB Type-C port's capabilities."
Leung then look a better took at Surjtech's cable, finding some answers to what caused his $1,499 Chromebook and other electronics to fry.
"I directly analyzed the Surjtech cable using a Type-C breakout board and a multimeter, and it appears that they completely miswired the cable," Leung wrote. "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."
He went on to urge Amazon customers not to buy this USB-C under any circumstances.
The damaging cable has since been removed from Amazon, although the review remains. While many might think this was a one-off case of a manufacturing problem, Leung later posted more problems with Surjtech's cable. This includes a 10 kΩ resistor used instead of 56 kΩ resistor, and the resistor was hooked up as a pull-down instead of a pull-up.
Leung really took one for the entire tech team on this one. We only hope he gets his Pixel 2 fixed soon to continue keeping cable manufacturers honest.
Source: Ars Technica
