USB-C Pinout

The USB-C port on an A1708 is constructed with from a metal cap, a PCB, and a pin carrier. The metal cap has a ground shield that extends toward the end of the port and kapton tape on the inside to protect against shorts. The PCB layer has indents in the sides of the ports to allow the USB C cable to grab on to. The pin carrier has a metal frame and shields that partially cover the exposed port like the metal cap does. The pins are held in place with a plastic. All three of these components are soldered together.

Common power sequence:

Common problems on Macbooks:

1. No External monitor, also Not able to charge / but USB connectivity works. In most cases means CC1 or CC2 pin is either damaged or dataline is burned on cd3215/17 side. There are usb 2.0 lines in the middle, they work fine in both orientations, thats why it somehow detects storage devices.
2. Charging works only in one orientation same with CC1/CC2, most likely damaged connector.
3. Charging works, data transfer too, no external screen with known-good cable Inspect dataline pairs for damage or shorts. Shorted dataline usually is a bad sign.
4. Damaged port, no image on the screen RIP CPU. Despite all possible precautions, it is possible to kill the CPU by sending 20V to some of Datalines around. In most cases it will blow the cd3215 but before replacing dead CD3215 check if there is a short on USB_UPC_PCH_XA( or B)_P(or N).