An USB isolator can help eradicate floor loops and minimizes electromagnetic interference (EMI) among the computer and the linked machine. 1x GND 3V3 (P2 with 2 pins 2.54mm) connector can be employed to energy externally the WCH CH569 MCU (it is usually recommended to remove the P4/SHUNT in that situation https://eu-pentestlab.co/en/