HP Color LaserJet Pro MFP 476dw: Firmware/NVRAM mismatch between formatter board and sub-components?

[SteffenMoser]

Short version:

I've exchanged the formatter board of a LaserJet Pro MFP 476dw due to a mechanical defect of the NIC port. The printer freezes while starting up with the new formatter board, but does well when going back to the original one. Cabling checked carefully. Firmware on the exchange board too old? Firmware mismatch? NVRAM?

Long version:

Hi all,

when moving my printer to another room, I mechanically damaged the RJ45 connector (a network cable was still connected and the plug bent-over) accidentally. As the printer is still fine, I bought a new formatter board as a replacement. It has exactly the same model number (CF387-60001) as the old one which was originally installed in my printer. So being not untrained with electronics, I carefully removed all wires and unmounted the old formatter board. Afterward, I installed the new one and gently plugged all cables and flat-cables into their correct positions.

After replacing the formatter, the printer asked me for the language, I chose English and then the display just froze. After waiting for some minutes, I powered it off. Since then it shows the following behavior when powering it on: The "HP" boot screen is displayed, when the progress bar is up to about 50%, the display turns dark, only the question mark is lighted and the attention symbol and another symbol in the upper right corner are blinking forever. It does neither accept a print job (besides the engine self-test which prints the line pattern beautifully!) nor does it get visible via WiFi, Ethernet nor is it recognized as a USB device. It is just dead. The touch screen does not react at all.

What works are the two types of "reset" as described in the "Repair Manual". When holding the lower left quadrant (or the lower right quadrant) pressed, it tells that the storage is initialized but afterward it just freezes again.

So I switched back to my original board: All works fine (besides the loose connection of the Ethernet port caused by the mechanical damage it has), so it is quite sure that I did not damage anything when changing boards.

Does anybody have an idea what could be the problem with the new formatter board? I have three ideas:

1) The new formatter board is just defective. I cannot test it, because I do neither have another printer nor another formatter board beside my original one. In this case, the dealer where I bought it from, should replace it.

2) I had the most recent firmware (from June 2019) installed on my printer. Is it possible that the firmware is distributed to the various subsystems and too new firmware versions on the subsystems cause trouble to the "new" formatter board (which seems to have been manufactured in 2012 and might have a very old firmware version installed)?

3) In the Repair Manual, it is stated that exchanging the DC controller and the formatter board at the same time must be done with care and in a step-by-step manner because both PCBs contain important information in their NVRAMs. So in my case, I have not changed the DC controller board, but only the formatter board. Nevertheless, there might be some implication: If I understand the statement in the Repair Manual correctly, then the printer copies the NVRAM setting from the longer-installed to the freshly-installed PCB. So is it possible that NVRAM data in the DC controller (written by the most recent firmware) might be baffling the formatter board with its possibly old firmware?

Any opinions on what I could do? Are there any possibilities to update the formatter board firmware separately?

Thank you very much in advance for any helpful comments!

Kind regards,
Steffen

[Repairatrooper]

Are you positive that this board was brand new and not a "pull" from a dead machine? If you can get into the service menus on the printer with the new board does it show a serial number? If it does and it is not the serial number of your printer then it is likely you were sold a used board not a new one. Are you certain that the board has the correct regionalization. My service manuals show the correct part number of CF387-60004 which is model specific for the 476dw. The part number you post shows as invalid in my order systems and might be a blank board that is supposed to be compatible with all M476 models but once installed would be tattooed for a particular model such as the DW or DN. 

[SteffenMoser]

Hi,

thank you very much for your quick reply!

Unfortunately, I cannot be 100% sure about the exchange board's history. I bought it as a new one, the seller confirmed it. I also don't get into the service menus with the new board because the printer freezes earlier. The part number of the exchange board is identical to the original one (on the sticker: CF387-60001, A-5337-46, on the board itself: CF387-80001). Exactly the same numbers, only the serial numbers differ, of course.

Kind regards,
Steffen

[SteffenMoser]

The seller is going to replace the Formatter Board I received. So we will wait and see what happens when mounting the new one...