The True Cost of Using USB-C Cables
Ashley Allen / 4 years ago
Remember the story of a Google engineer who declared war on USB-C cables that failed to meet specifications? His continuing battle took a turn so grim even he was surprised at how dangerous it had become. Back in November, Benson Leung, who works on Google’s Pixel range of computers – one of the first systems to support USB-C – found that many cheap cable available on sale failed to meet the official 1.1 specifications, and so began reviewing every cable he could get his hands on from Amazon.
Leung’s mission, though, has met an abrupt end. Not because he has reviewed every USB-C cable available, but because the last one he bought and tested destroyed his computer, as well as the two USB PD sniffers he was using for testing. He bought a Surjtech 3M USB A-to-C cable (now removed from sale) and plugged one end into his Chromebook Pixel and the other into the sniffer. The sniffer failed immediately, and the Pixel soon followed.
“Hi Benson here doing another USB Type-C legacy cable review. This one will probably be the last one I do for a little while because this cable (1-star review score, straight off) seriously damaged the laptop computer I am using for these reviews, a Chromebook Pixel 2015, and two USB PD Sniffer devices (Twinkie).
I plugged this cable into the twinkie (as a pass through) and my Chromebook Pixel 2015 and the A end into a 1st party Apple 12W iPad charger.
Twinkie’s current and voltage measurement command (tw vbus) failed immediately after plugging this cable with the adapter into it. This is permanent damage. 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.
On my Pixel, 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. 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.
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.
This is a total recipie [sic] for disaster and I have 3 pieces of electronics dead to show for it, my Pixel 2015, and two USB PD analyzers.
Needless to say, this cable is fundamentally dangerous. Do not buy this under any circumstances. I will be contacting Surjtech directly shortly.”
Remember, kids: if you’re buying a new USB-C cable, always check to see if Leung has reviewed it. It could save your devices from being fried.
Image courtesy of MacWorld.