Here's an error message that I found embedded in the output of hp-timedate a few days ago:
error: Unable to communicate with device (code=12): hpfax:/usb/officejet_5500_series?serial=MY3C1D11KS96I checked the USB cable connection and it looked OK. I listed the USB devices with lsusb and it seemed OK:
error: Unable to open device. Exiting.
Bus 001 Device 004: ID 03f0:3a11 Hewlett-Packard OfficeJet 5500 seriesI launched hp-toolbox and was surprised to discover that both the printer and fax icons appeared with a little red X-mark decoration. And sure enough, hp-toolbox insisted that both were unavailable.
I cycled the printer power, but to no avail. I considered rebooting my box, but then I had an idea - or, rather, I finally realized that I faced a very similar situation in the past. It all seemed very familiar. I tried running hp-timedate as root, and what-do-you-know - it worked.
So, this was a permissions issue. Again. I opened /usr/share/doc/hplip/NEWS.Debian.gz and found the following:
Access to the full functionality of hplip; ink check, toolbox,So I added myself to the lp group from the GNOME Control Center, using the "User and Groups" task, logged out and logged in, and then verified that I could finally manage the printer from my own account.
printing and scanning is now provided for members of the 'lp'
group. The use of the scanner group is depreciated.
Unlike the previous time, the permissions issue was documented alright. Not that it helped, but it's progress nonetheless. I guess.