Firmware 20210408 breaks HP Color LaserJet Pro MFP M476dw

[binary101010]

Prior to 20210408 firmware, the printer hums along with zero issues. Scanning works, printing works, it never complains and was a shining tribute to HP's quality printer engineering.

So recently, I found that there was a new firmware available to download for my printer. I should warn anyone doing a bit of research before attempting to install the April 2021 version of the firmware because it has caused random print jobs whether its from Microsoft Word or Adobe Acrobat to simply hang the printer. Printer display will indicate it is printing a document but nothing ever comes out. I've left a printer in this state for days with nothing coming out. Touch controls become unresponsive. The only resolution is powering off/on. Even then it sometimes gets stuck in the "Initializing..." stage of the printer startup.

Scanning is also dodgy with the only scanning software that works with it from HP's latest software/drivers download dated March 2021 (version 15.0.16078.631). All other HP software such as HP Smart no longer works with it.

Trying to reach out for support for an out-of-warranty printer is also another journey worthwhile mentioning. HP has a chat bot that leads you to a support page and as soon as you indicate that your printer is out-of-support, it asks you to use a WhatsApp number that has an auto responder that asks you to use another WhatsApp number. Trying to contact that second WhatsApp contact results in nothing. A vacuum. No one ever responds to it.

If anyone knows where I can download a previous version firmware for this printer, please, please, please let me know where. I would be forever grateful.

[Valsimot]

If you know how to upgrade/downgrade firmware with .rfu you can download an older version. Use CRTL+F to find the needed rfu file. 

ftp://ftp.hp.com/pub/networking/software/pfirmware 

You can find instructions on how to upgrade firmware with .rfu on google.

[binary101010]

Thank you @Valsimot. I'll let you all know how I went.

[SteffenMoser]

I can confirm this problem with my HP Color LaserJet Pro MFP M476dw as well. I am going to try the downgrade to 2018/2019 (?) version -- knowing that the newer release contains some serious security fixes:

https://support.hp.com/soar-attachment/918/col54144-releasenotefile20210408.html

The older file I still have in my archive is "HP_LaserJet_M476_Color_MFP_Series_FW_Update_20190401.exe".

[SteffenMoser]

The downgrade worked well, now I am back on version 20190401. Interestingly, I don't find anything about this version in the release notes files I linked in my last posting.

Let's hope HP releases a fixed version of the 20210408 upgrade!

[binary101010]

Downgrade worked.

I was holding back from posting anything as I am still in a period of testing. I noticed that one of the PCs which did not have the updated HP printer driver installed caused the printer to hang again. Another PC with the latest driver updated caused the printer to hang because of its filename (very peculiar). HP Smart still doesn't work so I am investigating that. Perhaps need an update.

Overall, so far, its better than the latest firmware which continually bricks the printer. At least its now 90% reliable. Will post another update soon.