After performing the Factory Reset, if USB detection is still a no-go, I would see if RMP can detect/play movies through a DLNA server. (ie. if your router is so equipped, you can place the USB in its USB 2.0 or USB 3.0 port and enable the DLNA server or UPnP and see if RMP sees and plays the videos). At least then can help narrow issue if RMP issue.