因此，我的列印掃描器 Samsung SCX-4300 透過 USB 工作正常，相反，我使用「網路 USB 伺服器」將其連接，如下連結：
透過伺服器，列印工作正常，但掃描器無法工作，我按照Ubuntu教程的說明進行操作：
https://help.ubuntu.com/community/SaneDaemonTutorial?action=show&redirect=sane.d+tutorial
1.所以我在終端上寫道sudo service saned restart：
Failed to restart saned.service: unit saned.service is masked
2.之後，sudo service saned status：
● saned.service
Active: inactive (dead)
Loaded: masked (/dev/null; bad)
然後上網查了一下，發現了這個網站：systemctl，如何取消屏蔽
3. file /lib/systemd/system/saned.service：
/lib/systemd/system/saned.service: symbolic lik to /dev/null
4.我打字查看sudo nano /run/systemd/generator.late/saned.service，發現完全是空的。
5. sudo rm /lib/systemd/system/saned.service然後，後來，sudo systemctl daemon-reload
7.最後，systemctl status saned：
● saned.service - LSB: SANE network scanner server
Loaded: loaded (/etc/init.d/saned; generated)
Active: failed (Result: exit-code) since Sun 2019-06-16 13:19:23 -05; 9min ago
Docs: man:systemd-sysv-generator(8)
Process: 923 ExecStart=/etc/init.d/saned start (code=exited, status=1/FAILURE)
jun 16 13:19:22 MS-7529 saned[923]: * Starting SANE network scanner server saned
jun 16 13:19:23 MS-7529 saned[944]: saned (AF-indep+IPv6) from sane-backends 1.0.27 starting up
jun 16 13:19:23 MS-7529 saned[944]: do_bindings: [1] bind failed: Address already in use
jun 16 13:19:23 MS-7529 saned[944]: do_bindings: [0] bind failed: Address already in use
jun 16 13:19:23 MS-7529 saned[944]: do_bindings: couldn't bind an address. Exiting.
jun 16 13:19:23 MS-7529 saned[944]: FATAL ERROR; bailing out, waiting for children...
jun 16 13:19:23 MS-7529 saned[944]: bail_out: all children exited
jun 16 13:19:23 MS-7529 systemd[1]: saned.service: Control process exited, code=exited status=1
jun 16 13:19:23 MS-7529 systemd[1]: saned.service: Failed with result 'exit-code'.
jun 16 13:19:23 MS-7529 systemd[1]: Failed to start LSB: SANE network scanner server.
8：於是我又去查了一下sudo nano /run/systemd/generator.late/saned.service：
# Automatically generated by systemd-sysv-generator
[Unit]
Documentation=man:systemd-sysv-generator(8)
SourcePath=/etc/init.d/saned
Description=LSB: SANE network scanner server
Before=multi-user.target
Before=multi-user.target
Before=multi-user.target
Before=graphical.target
After=remote-fs.target
After=dbus.service
After=avahi-daemon.service
[Service]
Type=forking
Restart=no
TimeoutSec=5min
IgnoreSIGPIPE=no
KillMode=process
GuessMainPID=no
RemainAfterExit=yes
SuccessExitStatus=5 6
ExecStart=/etc/init.d/saned start
ExecStop=/etc/init.d/saned stop
9.我再次輸入sudo service saned status：
● saned.service - LSB: SANE network scanner server
Loaded: loaded (/etc/init.d/saned; generated)
Active: failed (Result: exit-code) since Sun 2019-06-16 13:19:23 -05; 1h 20min ago
Docs: man:systemd-sysv-generator(8)
Process: 923 ExecStart=/etc/init.d/saned start (code=exited, status=1/FAILURE)
jun 16 13:19:22 MS-7529 saned[923]: * Starting SANE network scanner server saned
jun 16 13:19:23 MS-7529 saned[944]: saned (AF-indep+IPv6) from sane-backends 1.0.27 starting up
jun 16 13:19:23 MS-7529 saned[944]: do_bindings: [1] bind failed: Address already in use
jun 16 13:19:23 MS-7529 saned[944]: do_bindings: [0] bind failed: Address already in use
jun 16 13:19:23 MS-7529 saned[944]: do_bindings: couldn't bind an address. Exiting.
jun 16 13:19:23 MS-7529 saned[944]: FATAL ERROR; bailing out, waiting for children...
jun 16 13:19:23 MS-7529 saned[944]: bail_out: all children exited
jun 16 13:19:23 MS-7529 systemd[1]: saned.service: Control process exited, code=exited status=1
jun 16 13:19:23 MS-7529 systemd[1]: saned.service: Failed with result 'exit-code'.
jun 16 13:19:23 MS-7529 systemd[1]: Failed to start LSB: SANE network scanner server.
我找不到如何修復透過伺服器連接掃描器的問題。
那麼有誰知道如何解決這個故障呢？