During firmware flashing on your Original Prusa XL, you might get the message "USB drive not connected! Please insert a USB drive with a valid firmware file".
Error name: USB not connected
Error code: #17602
This issue happens when there is an error reading the USB drive.
Make sure that the USB drive is connected to the printer, and that the USB port in the Buddy board is not damaged. If the error persists, try using a new, FAT32-formatted USB drive.