HP 400 stuck initializing

Question edited for clarity. Full make model.

A factory reset won't fix firmware crashes or errors on updates. The firmware is what the machine does before the software is loaded and how it is loaded. A Reset, only reloads the operating software. Error 79 is an easy fix though. You will need to take it to an HP Service Centre if the firmware update is the issue.

It sounds like the printer is holding a print job in memory since it is showing " Printing Document" now on the display. Print Jobs are Stuck in the Print Queue. Disconnect any cables from the printer, except the power cable.

79 Error Message - HP LaserJet Pro 100 color MFP M175nw

https://h30434.www3.hp.com > td-p

HP LaserJet Pro - 79 Errors ' HP® Customer Support

https://support.hp.com > ca-en > document
Solution: 79 Service error Turn off then on ... If the message persists, disconnect any network or USB cables and power cycle. If the printer returns to Ready, ...

I would try what is suggested by EastTXTechDoc here... http://h30499.www3.hp.com/t5/Printers-LaserJet/LaserJet-Pro-400-M401dn-79-SERVICE-ERROR/td-p/6415530#.U6xCBdIg__8

Would appear that either someone has put in some bad memory or the memory that came with it has gone bad:-

You could try taking the memory out to eliminate it.

79 Service error

Description

An incompatible DIMM is installed.

Recommended action

1. Turn the product power off.
   

2. Install a DIMM that the product supports.
   

3. Turn the product on.
   

If the message persists, contact HP support.

I had the 79 service error on my Laserjet pro 200 m276nw. The manual says this is "The product has experienced an internal firmware error." and gives no further diagnostic steps. Thanks HP for nothing!

Repair manual downloads:
https://www.printersupplies.com/amfile/file/download/file/20/product/5896/
https://www.laserexpressinc.com/manuals/HP/hp-clj-pro-200-m276-troubleshooting-manual.pdf

The initial symptoms was that it would randomly restart and then get stuck in the 79 error. If you turned the printer off and on, it would get stuck in the 79 error about half the time. It would get to the part where it runs the sheet scanner motors with a kind of sickly sound and then just quit.

To view the diagnostic Error Report log on the secondary service menu
Click on setup icon,
Touch middle left below home button and lower right below question mark.
to activate 2nd service menu to print error report

The Error Report had an error:
Abort
Task: IO_usbhost_urb_complete

I found that all of the boards for this printer are relatively inexpensive, so I bought every board for this printer on Ebay.

HIgh Voltage Power Supply: RM1-8705 HVPS $24.95
Fuser Power Supply RM1-8709-000CN $20.00
Formatter w/wireless card CF224-60001 $42.00
DC Controller RM1-8704 $25
Low Voltage Power supply RM1-9012-000CN $34
Universal Serial Bus (USB) CF368-60001 $13

Things only got worse. The yellow toner stopped working and the remaining colors were out of alignment. It would also only print in black and white. It then began to print solid black pages. I was about to give up, so I began putting the old boards back in since it seemed to be getting worse after spending $159 on parts.

I replaced the formatter board which didn't do anything. Then I replaced the DC Controller board and BINGO, that seemed to fix the printer. I don't think the board itself was defective, but maybe there was a loose wire or connection that eventually fixed itself with the install/uninstall process. I'm still not sure and I'm not going to mess with it while it is working since these multi-function printers are expensive to replace. So, if you get the dreaded 79 error, you might try to unplug/plug every connector to make sure everything is tight.

79 Error Turn off then on
Description
The product has experienced an internal firmware error. Under most conditions, the product
automatically restarts.
Recommended action
Turn off the power by using the power switch, wait at least 30 seconds, and then turn on the power
and wait for the product to initialize.
If a surge protector is being used, remove it. Connect the product directly into the wall socket. Use the
power switch to turn the product on.
If the error persists, contact HP. See www.hp.com/go/LJColorMFPM375 or www.hp.com/go/
LJColorMFPM475 or the support flyer that came in the product box.

Firmware issue:
1. Cancel all pending/que jobs
2. Disable nesting option
3. Dis connect data cable, restart the machine.. check...
4. Up load latest firmware.( read carefully read me file before up loading the firmware)

The 79:04 error is a "GENERIC FIRMWARE" error.
Go to www.hp.com support and drivers and update the printers firmware.