As described in this review, there are at least three versions of the JUCX03 at Best Buy. Unfortunately, they all have the same problems reported in this review where no USB or display enumeration or even charging happens when the j5create JUCX03 USB 3.1 Type-C to Type-C Cable is used to connect the OWC Type-C Dock with the Apple MacBook (Early 2016).
Let's take a first look at the problems seen with the j5create JUCX03 USB 3.1 Type-C to Type-C Cable.
Using USB Power Delivery analysis software from Granite River Labs, we observe that the USB Power Delivery contract is happening but the Alternate Mode entry is not happening correctly. Looking at the USB Power Delivery protocol trace more closely, we see the following sequence:
1) PD Contract is completed on the MacBook side
2) MacBook initiates Alt mode and the OWC Dock acknowledges
3) However, the MacBook Alt mode is not acknowledged by the OWC Dock
4) Since the Alt mode entry is not acknowledged, the Mac is trying to so a soft reset. For some reason the soft reset is not acknowledged by the OWC Dock
5) The MacBook then issues a hard reset. The OWC Dock resets and sends the source capability again
6) Everything seems to be really messed up at this stage and the MacBook doesn't even send any Good CRC's, so no PD contact happens after this
As a result of the constant resets going on, you can hear the Apple MacBook (Early 2016) sometimes beeps a few times right after the cable is connected as if someone keeps on connecting in and out a display.
Because of this USB Power Delivery negotiation failure, no USB or display enumeration occurs and no power charging happens.
When we replace the j5create JUCX03 USB 3.1 Type-C to Type-C Cable with the j5create JUCX01 USB 3.1 Type-C to Type-C Coaxial Cable, we see much better results.
With the j5create JUCX01 USB 3.1 Type-C to Type-C Coaxial Cable, the USB PD and Alt Mode negotiations all are happening correctly and we see the OWC Type-C Dock charging the Apple MacBook (Early 2016) at 30 watts (20 volts @ 1.5 amps).
The reset issues seen with the JUCX03 no longer exist with the JUCX01.
We can also see proper USB and display enumeration in the Mac's System Information.
Note the same problems are seen with the JUCX03-1A, JUCX03-2A, and JUCX03-3A versions of the same cable.
The moral of this story is that next time you are at Best Buy looking for a USB Type-C to USB Type-C cable, it's a better bet to purchase the j5create JUCX01 USB 3.1 Type-C to Type-C Coaxial Cable instead of the j5create JUCX03 USB 3.1 Type-C to Type-C Cable.