MacBook Pro A1708 USB devices not working but charger works repair

Problem description
USB devices not working when plugged in although charger works

Symptoms

 * #incomplete

Solution
This board has a USB redriver chip which is not present in the schematic and boardview. It is located right next to the USB connector, on the opposite side from the CD3215s, next to U2800. Marking on the chip is PI3USB32224BXEAE. If it dies, it prevents USB communication with devices. Often times you can see a hole on the chip. Replace it!