my brother hl-l2350dw works on usb but not on ethernet. the network light isn't on. is it broken?

Diagnosis

The absence of the network light on your Brother HL-L2350DW indicates a failure in the Physical Layer (Layer 1) of the OSI model. This means the printer's network interface card (NIC) is not detecting an electrical signal from the router or switch. When the printer works via USB but fails on Ethernet, the internal logic board is functioning, but the handshake between the printer's 10/100 Mbps port and your network hardware is failing. This typically happens due to one of three reasons: a faulty Cat5e/Cat6 cable, a disabled port on the router, or an "Auto-MDIX" negotiation failure where the router cannot determine if the printer is a host or a node. If the light is completely dark, the printer doesn't even see a connection; it isn't a software or IP address issue yet, but a hardware connectivity break. You can confirm this by swapping the Ethernet cable with one that is currently working for another device, such as a gaming console or a PC.

How to Fix It

Follow these precise steps to establish a hardware link and verify the network connection:

1. Power down the HL-L2350DW completely by pressing the Power button and unplugging the AC power cord from the wall.
2. Disconnect the Ethernet cable from both the printer and the router. Inspect the gold pins inside the printer's RJ-45 port for any bent or corroded contacts.
3. Use a known-working Category 5e or Category 6 cable. Avoid using "flat" Ethernet cables for this specific model, as they often lack the shielding required for stable negotiation with Brother's NIC.
4. Plug the cable firmly into the printer and then into a LAN port on your router. If you are using a managed switch, ensure the port is set to "Auto-Negotiate" and not locked to 1000Mbps (Gigabit), as this printer only supports 10/100Mbps.
5. Plug the printer back into the power outlet and turn it on.
6. Observe the network light. If it illuminates, the hardware link is established.
7. To ensure the printer is actually communicating, press the [Go] button three times quickly to print the Network Configuration Report. Look for the "Node Name" and "IP Address" sections; if the IP is 0.0.0.0, the hardware is connected but the DHCP handshake failed.

If That Didn't Work

• Perform a Network Reset: Enter the printer's internal menu by pressing [Menu]. Navigate to [Network] > [Network Reset]. Select [Yes] to reset all network settings to factory defaults. This clears any static IP conflicts that might be preventing the light from triggering.
• Bypass the Switch: If you are using a network switch or a wall jack, plug the printer directly into the main router's LAN port. Many "Green Ethernet" switches put ports into a deep sleep mode that the HL-L2350DW cannot wake up from, resulting in a dark network light.
• Assign a Static IP via Web Interface: If the light is now on but you can't print, find the IP address on the printed report, type it into a web browser on your PC, and navigate to the "TCP/IP" tab. Change the Boot Method from "TCP/IP Auto" to "Static" to prevent the printer from losing its connection when the lease expires.
• Check for Driver Conflict: Uninstall the "Brother HL-L2350DW series" driver from your PC and reinstall the "Full Driver & Software Package." Often, Windows installs a "Class Driver" via USB that blocks the network port from being recognized as a valid print queue.

Heads Up

• Cable Length: Ensure your Ethernet run is under 100 meters (328 feet). Beyond this, the voltage drop can cause the network light to flicker or remain off.
• Avoid Power Strips: Plug the printer directly into a wall outlet. High-interference power strips can occasionally introduce electrical noise that affects the sensitive NIC on the HL-L2350DW.
• Firmware Updates: Use the Brother Firmware Update Tool on your PC to ensure the printer is on the latest version, as early revisions of this model had known issues with certain Gigabit router brands.
• IPv6 Conflict: If your network is older, go to [Menu] > [Network] > [IPv6] and set it to [Off]. This can resolve "ghost" connection issues where the light is on but the printer is unreachable.