Downgrading to older bios version on HP Z420 - help required

[Plebestrian]

Hello everyone,

I am currently on the latest bios version 3.96 on a Z420 and would like to downgrade to a previous version (due to various problems i'm not going to further elaborate on). My attempts over the past few hours have all ended in vain. I've tried various past versions (3.95, 3.88, 2.54, 1.23 iirc) and every method in my knowledge (the windows application, DOSFLASH and using the in-bios tool).

DOSFLASH returned "System ROM image is invalid" with every version apart from 3.96, which I at some point tried to see if the utility actually works. The windows application ended in an error every time. The in-bios tool *immediately* reported a successful flash for versions 3.95 and 3.88 without actually changing anything and declared older versions as invalid. Again the in-bios tool seemed to work for flashing 3.96, for which it at least took some time and indicated percentage of completion (not that anything could have changed).

Is there any alternative way of flashing older bios versions to this machine short of directly plugging onto the bios chip?

Any help would be greatly appreciated.

[BeemerBiker]

From the release history of 396:

---

Version 3.90

WARNING: After installing this BIOS version onto the system, prior BIOS versions cannot be installed onto the system.

---

However, 395 should have been installable in addition to 394, and 392

Possibly the warning about not being able to go back was omitted from 396 by mistake.

Where did you find the link for the 395 bios?  Was is saved automatically when you upgraded to 396?

[DGroves]

downgrading your HP bios will not fix any issues/problems it will however introduce some issues/problems that are fixed in the latest bios

hp makes it almost impossible to downgrade for a reason

you might get a useable reply/help if you stated just what issue you are having

many people try downgrading thinking a earlier bios without the specter fixes will make the system faster, they are unaware that both windows/Linux check for this and if the fix is not enabled in the bios the OS'S will load the necessary patchs

[Plebestrian]

>Where did you find the link for the 395 bios?

It's the only older version of the bios that's still on HP's website,.As for the other versions, hp ftp links or softpedia.

[Plebestrian]

>you might get a useable reply/help if you stated just what issue you are having

Mainly overclocking through XTU or Throttlestop not working anymore with an e5-1650, which it did with whichever pre-2013 bios version I had before (bios settings identical). I initially updated the bios in the hopes of getting an E5 2680 v2 to work, which of course it didn't. I expected as much, because why would HP add the microcode for the 26-series if that means less sales of more expensive systems (/rant).

I take it there is no practical method of downgrading apart from either soldering on a different bios chip or flashing with external hardware?

[DGroves · Accepted solution]

before i answer you latest question, I'd like you to consider this:

the the modest overclock you might get using XTU on your current cpu worth killing your motherboard? board replacements are not that cheap would it not make more sense to simply get a faster cpu

it is possible to force a downgrade, but the procedure is complex and unforgiving once started it must finish successfully or you will have a non working board in other words starting the process and then trying to stop it will leave you with a non working board

it involves using the motherboards crisis recovery jumper when flashing i don't remember the details as i personally see no benefit in risking a working board for a small overclock but since it's your board it's your choice check the forum for previous posts on bios recovery and you may find what your looking for

[Plebestrian]

Thanks a bunch in advance, i'll get back with results when I have the time.

[BeemerBiker]

You might want to read through this thread

https://winraid.level1techs.com/t/bios-mod-requested-for-hp-z420-with-lga-2011-socket-intel-c602-chi...

You might want to join the forum and ask about the v2 cpu upgrade that that one author mentioned.

There is a very good discussion of booting from z420 NVMe here that explains bios mods also.

https://h30434.www3.hp.com/t5/Desktops-Archive-Read-Only/Simplified-Installation-of-M-2-NVMe-Drives-...

as @DGroves mentioned there is a good chance to ruin your motherboard.

[Plebestrian]

(Edit: additional clarifications and, after reading the replies I feel it's necessary to add:

This is what worked for me with an HP Z420 workstation. The procedure will obviously differ for other models. no sh*t.)

Happy to report that I did in fact not brick my system and everything went unexpectedly smoothly considering all the discouragement. Three times no less (3.96 to 3.95 to 3.88 to 3.65, in other words until i found a version that let me overclock the 1650). 

For future readers:

Reverted to Bios version 3.65 (ftp://ftp.hp.com/pub/softpaq/sp64501-65000/sp64992.exe)

using the step guide at the end of the OP (first post): https://h30434.www3.hp.com/t5/Business-PCs-Workstations-and-Point-of-Sale-Systems/Crisis-Recovery-Ju...

Don't pull out the USB stick during step 7 and disregard step 8 onwards.

Instead wait until the system finishes the flashing screen (percentage bar) and shuts down.  Pull the power cord before it attempts to restart.

Reset the jumper to its original position and (optional) remove the USB stick.

Afterwards power on as usual being greeted by your new(older) bios version in the bottom left corner of the splashscreen. Congratulations.

[SDH]

For future readers... Plebestrian refers to the steps in the "OP", the original first post, from that thread. As noted HP does not detail clearly the option of downgrading BIOS to an older version this jumper-position-change way for any of the ZX20 family of workstations but HP did provide a bit of info on the process in the Z820 technical manual. Be careful on the default jumper positioning. It is different for the Z820/Z840 versus all the other workstations in those two families.

I again encourage all BIOS manipulators to learn how to update BIOS from within BIOS for best safety, and I continue to see small but potentially significant possible errors in the HP directions on how to upgrade BIOS from within BIOS. BIOS is a primative OS, and as such only knows what is programmed into it. HP has at times "conflated" methods for the ZX40 into those for the ZX20, and more recently appears to have conflated methods for the ZX20 into the ZX40 instructions.

To be clear... the .bin file for BIOS upgrade is to be on the "top" level of a USB drive or CD-ROM if you're upgrading from within BIOS for a ZX20 family workstation, and unless things have been reprogrammed recently by HP it is to be in the lowest level of a nest of three directories (folders) on a USB drive for a ZX40 workstation and beyond.

I need to check on whether HP has changed BIOS upgrading from within BIOS on the ZX40 workstations because their directions now clearly indicate that BIOS upgrade from within BIOS can be done the older ZX20 way that did not work when I tried that on Z440/Z640 workstations some years ago. I will add an update shortly.