Problems with Nikon scanner and Mac
I have a Nikon Coolscan V ED (also named Coolscan 50 ED in some countries) which used to work fine with my iMac. (24" w. mountain lion and Vuescan software)
After connecting it to a new Imac (27" with same software) I can´t communicate with it anymore. It is not seen i Vuescan, and not seen in as a USB device either. Same problem when I connect to the old Imac as well, and even to an Mac mini with OS x 10.6.
I have tried with 2 different USB-cables as well, and one of them is tested to work fine when connected to a USB printer.
To me it sound like a hardware problem with the scanner, but maybe there are other options?
Is there a way to check the scanner for hardware failure without sending it for repair?
1) Are you running the newest version of VueScan? Had a similar problem on an older MacPro under 10.7.3 - the newest version works fine.
2) Check ports, don't run from a hub (just typical USB troubleshooting), change cables.
Remember with Vuescan the scanner has to be hooked up and powered on before opening the software. If not, Vuescan wont see it and install a compatible driver. The fact it now wont work on your old imac or a mini leads me to believe bad usb cable, or it needs sent in for repair.