Comment 7 for bug 1747060

Hi brian_p,
sorry for a bit long time to replay.

Here are the answers:
When the device is unplugged and without sudo command:
sane-find-scanner

  # sane-find-scanner will now attempt to detect your scanner. If the
  # result is different from what you expected, first make sure your
  # scanner is powered up and properly connected to your computer.

  # No SCSI scanners found. If you expected something different, make sure that
  # you have loaded a kernel SCSI driver for your SCSI adapter.

could not open USB device 0x8087/0x8000 at 002:002: Access denied (insufficient permissions)
could not open USB device 0x1d6b/0x0002 at 002:001: Access denied (insufficient permissions)
could not open USB device 0x8087/0x8008 at 001:002: Access denied (insufficient permissions)
could not open USB device 0x1d6b/0x0002 at 001:001: Access denied (insufficient permissions)
could not open USB device 0x1d6b/0x0003 at 004:001: Access denied (insufficient permissions)
could not open USB device 0x0bda/0x0139 at 003:004: Access denied (insufficient permissions)
could not open USB device 0x13d3/0x5188 at 003:003: Access denied (insufficient permissions)
could not open USB device 0x03f0/0x094a at 003:018: Access denied (insufficient permissions)
could not open USB device 0x04f3/0x010c at 003:008: Access denied (insufficient permissions)
could not open USB device 0x1d6b/0x0002 at 003:001: Access denied (insufficient permissions)
  # No USB scanners found. If you expected something different, make sure that
  # you have loaded a kernel driver for your USB host controller and have setup
  # the USB system correctly. See man sane-usb for details.

  # Not checking for parallel port scanners.

  # Most Scanners connected to the parallel port or other proprietary ports
  # can't be detected by this program.

  # You may want to run this program as root to find all devices. Once you
  # found the scanner devices, be sure to adjust access permissions as
  # necessary.

dpkg -l |grep libsane
ii libsane:amd64 1.0.25+git20150528-1ubuntu2.16.04.1 amd64 API library for scanners
ii libsane:i386 1.0.25+git20150528-1ubuntu2.16.04.1 i386 API library for scanners
ii libsane-common 1.0.25+git20150528-1ubuntu2.16.04.1 all API library for scanners -- documentation and support files
ii libsane-hpaio:amd64 3.16.3+repack0-1 amd64 HP SANE backend for multi-function peripherals

dpkg -l |grep libpam-systemd
ii libpam-systemd:amd64 229-4ubuntu10 amd64 system and service manager - PAM module

ls -l /lib/udev/rules.d/|grep hpmud
-rw-r--r-- 1 root root 921 mar 29 2016 56-hpmud.rules

So the answer seems to be yes to your questions, they are already installed.
I'm a bit confused, printer worked out of the box (except duplex but this was just one option to be set and good to go). But scanner is not working or discovered by any tool? Weird..
I mean, shouldn't it be the case that device is being seen and only driver is missing?

Regards,
Marcin