Appendix A: How to troubleshoot SE 79:04

Network related SE79:04

Most HP Designjet printers have built-in networking capabilities. Network settings can be set manually, but in the majority of cases, they are obtained automatically from the printer. These settings include many different fields, such as IP address and subnet mask, available gateways, host and domain names, etc.

In some cases, there can be issues in the firmware that can cause a certain value in one of these fields to be interpreted incorrectly, and this can lead to a 79:04 system error.

Symptoms

There is no single set of symptoms that can absolutely pinpoint a network related 79:04 system error. However, the following guidelines can be applied:

„It can happen at start up or when accessing the Network Configuration section of the FP

„In both cases, repeating the action with the LAN cable disconnected does not cause the 79:04 to occur

Solutions and workarounds

In the majority of cases, these issues will be due to an issue in the printer’s firmware. As soon as the conditions where the issue happens can be understood, it should be escalated to the GBU through the GCC.

At the same time, the following short term solutions and workarounds can help the customer to get up and running in the shortest possible time:

1Disconnect the network cable to be able to boot the printer and change network settings

2In the Network configuration menu in the Front Panel, disable any protocols that you are not using, including IPv6, SNMP and WebServices.

3If step “2” does not work, try setting a manual configuration of the device: a Enter the correct subnet mask and an IP in the valid range

b In the GateWay field, set the same value as in the IP address field c Do not set a host name or a domain name

4If step “3” does not work and the customer is using the network card which is part of the printer, try using an accessory Jetdirect card instead.

User Interaction related SE79:04

In some cases the printer may not react as expected when a certain set of conditions coincide. In these cases, if the printer doesn’t know how to react, it may simple display a 79:04 system error and force a reboot. Some examples (not real) that can help to illustrate this:

„An error occurs when a job is cancelled when it is at the “Finishing print” state and when the queue is disabled

„An error occurs if the Window is opened while the printer is checking the printheads

HP Designjet T Series — Service Manual

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