I am designing a custom Arduino Nano. I followed the Schematic from the official website. Attached is the schematic and the pcb layout for the section of usb-serial bridge. After the pcb was fabricated and assembled, i keep having this error message "unknown usb device (device descriptor request failed) " when i connect usb to my pc. i have tried using different usb cable and pcs but same story. What is the possible cause to this problem and what can i do to make it to work normally?
Thank you.
