This is pretty much off topic except that it has to do with connecting a USB scanner under linux.
But I know there are some good hardware people on this list so... I just bought a second hand Epson USB scanner. When plugging the usb cable in I bumped the end of the cable against the metal plate on the back of my computer and noticed a small spark. Tapping the end of the cable against the metal produces more small sparks when it connects. Now I don't have a multimeter here so I can't check, but I guessing that the metal shield on the USB plug should NOT be carrying current. Only the internal pins should be powered, so I shouldn't be seeing sparks right? I've swapped out the USB cable and it still happens. Any suggestions? Wiring problem on the scanner? Thanks, Phill
