My client’s Dell 1720dn Mono Laser Printer had been re-located and physically connected to a new router on a different IP segment. 192.168.1.x to 192.168.0.x which stopped communications with the local PCs which were updating their own IP addresses (DHCP) successfully. The printer’s fixed IP could be seen by printing the configuration reports but the old style ‘flashing lamps with two button menu’ system is difficult to use under pressure! The Solution to Fix this is a factory reset:

1. Power off the printer
2. Open the front cover (push the button on the left side)
3. Press and HOLD both the ‘Cancel’ and ‘Continue’ buttons (Right-Triangle + Red Cross)
4. Continue to hold the buttons and power the printer on.
5. Continue to hold the buttons until all light cycling activity has stopped.
6. After the lights have stopped cycling  and the “Error LED” light on the control panel is solid (could take up to 30 seconds), release the buttons.
7. Close the front cover to complete the Factory Default reset process.

YouTube Video Demonstration

A possible alternative fix that I didn’t try:-

1. There is a utility on the Install Disk to set a static IP address. Connect the network cable and power on the printer.
2. Press and hold the Continue button for 2-3 seconds to print a network settings report.
3. Obtain the MAC address of the printer from the network settings report. The MAC address is the value listed under the Standard Network Card section as UAA.
4. Insert the Drivers and Utilities CD.
5. When the Drivers and Utilities CD screen appears, click the Set IP Address link.
6. When the Set IP Address Utility window appears, enter the MAC address in the box under Discover Print Servers, and then click Discover.
7. Click to select your printer in the box under Configure Print Servers, and then click TCP/IP Settings.
8. When the TCP/IP Settings appears, enter the TCP/IP Address, Subnet Mask, and Gateway Address.
9. Click Apply to save the settings, and then click Close to exit the utility.