Power off the copier.
Disconnect both ends of usb cable between UI and net controller.
Then plug one end of usb cable in usb port of your laptop / desktop.
Same for the other ends. If the computer recognize both ends you can reconnect the usb cable in machine and check it is work.
If the computer dont recognize the ends then the usb cable is the problem.
Check also the cable between UI interface and CCM.
yes in fact there is a couple of errors 3-347 and 3-316 are repetitive. In other machine i can repair it easy the hdd was defective and the port usb 0 too, but in this case i can't do it. i change the software from alternet boot, pws with DC 102 software upgrade and i fail in the alternet boot only appper "ess is operational" that`s all only this
thanks for your time