Laserjet Pro MFP M479fdw wont go into sleep mode when connected to Mac

[SorenKirkegard]

Just bought a new all in one printer. Connected to iMac with USB cable. Everything seams to work as advertised except it won't go into sleep mode unless I disconnect the USB cable which kind of defeats the purpose. Tried unplugging the power cord and doing a reset. Tried a different USB cable but no effect. Starting to wish I had gone with the Canon model.

[Repairatrooper]

That it goes to sleep when disconnected suggests that some type of communication is happening that keeps the printer awake. This might be an issue that HP will address with an update if they are made aware of it, however a temporary work around you can try would be to turn off USB as one of the options that can wake up the printer, but this would then require you to touch the control panel to wake it up.

[TheMick]

There are several messages (some recent and some older) about this problem. I think I solved my printer's inability to go to sleep by disabling DHCP on both the wireless and wired network connections.

I have a rather hybrid set-up with Linux, Mac, and Windows all represented on my wifi network and the HP printer also connects to the network wirelessly. My printer is not connected at all by USB or ethernet.

The printer currently has a static IP for my wireless network; despite the static IP, I noticed in my server's syslogs that the printer was still occasionally requesting an IP address over DHCP:

Jun 1 15:15:10 printer.lan dhcp_server: dsrv: _dhcp_server_addr_mgmt_janitor_cb fired
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: _dhcp_server_addr_mgmt_janitor_cb | wrote correct number of bytes: 4
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_entry() | select() returned (ENTERING 'ret > 0') !
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_entry() | Recv'd a dhcp_server_read_fd event!
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_entry() | read > 0 bytes on dhcp_server_read_fd event: 4
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_entry() | dhcp_server_fd_msg: 1
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_entry() | calling DHCP_SERVER_janitor
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_janitor() | enter
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: dhcp_server_addr_mgmt_janitor() got called
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_janitor() | exit
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_entry() | Done with dhcp_server_read_fd event!
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_entry() | select() returned (LEAVING 'ret > 0') !
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_entry() | Set dhcp_server_link_fd in RD_FDSET!
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_entry() | Set dhcp_server_socket socket (47) in RD_FDSET!
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_entry() | Set dhcp_server_fd (155364) in RD_FDSET!
Jun 1 15:15:10 printer.lan dhcp_server: dsrv: DHCP_SERVER_entry() | Calling select() with NULL timeout!

Why is the printer still requesting an IP address? Then I remembered the Wired interface. Assigning the Wired interface an IP address appears to have done the trick.

From the web interface:

Network -> Wired (802.3) -> IPv4 Configuration -> Manual IP. I used a class C private IP (192.168/16) as my wifi network uses class A (10/8).

There is also an option under Advanced to disable the Wired interface completely, but I don't want to chance that yet until I have a better understanding of the printer out of fear I might not have a means of accessing the printer's web interface. I suppose one would disable the Wireless interface is the printer is connected over ethernet or disable both interfaces if connected by USB.