On Fri 21 Apr 2017 at 22:15:08 +1000, Ben Finney wrote: > On 20-Apr-2017, Brian Potkin wrote: > > On Fri 21 Apr 2017 at 06:05:02 +1000, Ben Finney wrote: > > > On 20-Apr-2017, Brian Potkin wrote: > > > > cat <printer-ready_file> > /dev/usb/lp0 > > > > > > There is no such device node: > > > > > > $ find /dev -name 'lp0' > > > > > > $ ls /dev/usb/lp0 > > > ls: cannot access '/dev/usb/lp0': No such file or directory > > There was *no directory* named ‘/dev/usb/’. > > That turned out to be key to me figuring out this mystery: The USB > hub's power had come unplugged. It was responding to some devices, but > not all.
Great. I bought a packet yesterday containing what I thought was an SD card and a micro SD card. 'lsblk' showed nothing when I plugged the "SD card" into slots on the readers I have. Before returning it to the shop I purchased it from I consulted a friend. He pointed out the word "adapter" on the "SD card" and asked why I hadn't plugged the micro SD card into it! > Now that I have the USB hub properly plugged in: > > * The ‘/dev/usb/lp0’ node appears. > * The ‘lsusb’ output shows an entry for the USB-connected printer. > * The ‘cat ~bignose/testq-out > /dev/usb/lp0’ command prints the file. All systems go, then. > That leaves the problem of failing to print to the HP printer > connected via 802.11, which would not be affected by the USB hub. I > will try again later to diagnose that one. Consider using the output of 'avahi-browse -art' as a diagnostc. Regards, Brian.
