Fix USB-C Extension Problems With This One Trick

Photo by Mishaal Zahed on Unsplash

Today, computer parts arrived. It's mostly cables because I wanted to use my PC's peripherals on my work machine (2017 MBP). My peripherals are connected to a USB switch, (which switches between PC and Mac), then to a USB-C hub (whose HDMI out is connected to my screen), then to a USB-C extension cable, which is plugged to my Mac. Then, when I tested the connection...

The Mac won't detect my peripherals.

I tested everything, from removing the USB-C extension cable (eliminate the possibility of the extension cable being dead), to stripping down to just the keyboard and mouse (eliminate possibility of insufficient hub power). Even tested on the PC (eliminate possibility of dead peripherals). I can't test the dongle because I don't have any other USB-C thunderbolt devices, but the HDMI out and power seem to work. Then I did the unthinkable:

I flipped the USB-C cable...

And it worked! Specifically, I flipped the female end of the extension cable, the one connected to the hub. I do vaguely remember reading something somewhere that some USB-C extension cables may not be reversible at all, that the solution was to just "flip the connector". It's also odd that only the USB devices didn't work. If the data lines were borked, HDMI out shouldn't have worked. And if only the pins on one side of the connector was operational, then power shouldn't have worked either.

Oh well... hope this helps someone having difficulties with USB-C extension cables.