System error 79:04 "Firmware Error", indicates the HP Designjet 800 or 500 series printer experienced an unexpected error and could not continue. Follow the steps below to troubleshoot the problem.
Troubleshooting HP Designjet 800 and 500 series printer functionality
Turn off and turn on the HP Designjet 800 and 500 series printer. If the error persists, go to Step 3.
Send a test print from the printer driver. If it prints successfully, go to software troubleshooting . If it is unsuccessful, proceed to Step 3.
Turn off the HP Designjet 800 and 500 series printer and disconnect the parallel cable and any network cables, leaving only the power cable connected.
Turn the HP Designjet 800 and 500 series printer on and send the Troubleshooting Print from the Ink System menu of the front panel. If the Troubleshooting Test Print is successful, go to troubleshooting connection . If the error reappears when performing the Troubleshooting Print, there may be a hardware problem with the printer.
Remove any additional memory. Send the Troubleshooting Print.
CAUTION: Before handling a memory module, HP Jetdirect or accessory card, put on a grounding wrist strap and attach the end to the metal chassis of the printer. If a wrist strap is not available, touch the outer metal surface of the printer with your hand. Otherwise, static electricity from your body could cause damage.
Remove the HP Jetdirect card if installed. Send the Troubleshooting Print.
Remove the HP-GL/2 Accessory card if installed. Send the Troubleshooting Print.
Check for a new release of the firmware and upgrade to the latest version if needed.
If the error persists, press the MENU button when the error appears to obtain further information for HP Customer Care technical support.
