Debugging USB device issues

People, I didn't get a response to my previous Q re an apparent problem with getting gphoto2 to work with my GoPro Hero 4 Session camera - I hadn't used the camera for a while and I thought maybe the Fedora upgrades since then were the cause of the problem - but maybe the problem is actually with the USB port on the camera? (gphoto2 used to work). The camera actually charges OK through the port and I can record videos and then move them to Fedora by moving the SC card to a card reader, mounting the dir and copying video files to the HD so the camera itself and device charging seems to be OK. I am getting nothing recorded in /var/log/messages when I plug in the GoPro and push its power button (plugging in any other USB device is working of course) so maybe it is the USB port on the camera that is the problem? - is there any way to debug that from the Fedora workstation? Thanks, Phil. -- Philip Rhoades PO Box 896 Cowra NSW 2794 Australia E-mail: phil(a)pricom.com.au