Z790 Hero BIOS downgrade

[Tron64]

I've upgraded my Z790 Hero from BIOS version 0703 to 0813.

Before the update, my RAM runs stable at 4000 MHz. With 0813, it looks like I have to reduce the speed to 3400 MHz (memtest is still running).

Tried to downgrade to 0703. It says the BIOS file is invalid.

Is it possible to downgrade BIOS from 0813 to 0703?

[JohnAb]

The 790 guys will be better able to advise you, but if it says invalid BIOS, then perhaps not 😞

Having said that, you might be able to downgrade to earlier versions of 08xx. iBruceypoo had said that he found 0806 and 0809 to be good on another thread (his playtime thread, should be near the top of the thread list here).

[skorell]

Tron64 wrote:
I've upgraded my Z790 Hero from BIOS version 0703 to 0813.

Before the update, my RAM runs stable at 4000 MHz. With 0813, it looks like I have to reduce the speed to 3400 MHz (memtest is still running).

Tried to downgrade to 0703. It says the BIOS file is invalid.

Is it possible to downgrade BIOS from 0813 to 0703?

Did you rename the Bios as per notes?

Before running the USB BIOS Flashback tool, please rename the BIOS file (MZ790H.CAP) using BIOSRenamer."

[JohnAb]

skorell wrote:
Did you rename the Bios as per notes?

Before running the USB BIOS Flashback tool, please rename the BIOS file (MZ790H.CAP) using BIOSRenamer."

Good point, I hadn't considered that possibility...

[Tron64]

skorell wrote:
Did you rename the Bios as per notes?

Before running the USB BIOS Flashback tool, please rename the BIOS file (MZ790H.CAP) using BIOSRenamer."

Yes, I always use the renamer executable. I even tried with 2 different sticks. The MB bundled stick still had the 0703 firmware (exactly the one which was used previously to upgrade to 0703.

[JohnAb]

If you want to try some of the other 08xx BIOS versions, you can find them in this thread: https://www.overclock.net/threads/official-asus-strix-maximus-z790-owners-thread.1800191/page-85

Right then, if 0813 is not working for you and you cannot downgrade to 07xx, then perhaps you could try 0806 or 0809, only because iBruceypoo had good experiences with them... but remember that they are not 'official' in the sense that they are not on the support page. However, I believe they are made available by Shamino as 'release candidate versions' to try at your own risk. He works for ASUS and is on the BIOS team. I'm not recommending you do this of course, just trying to give you options. Your choice of course and as a humble 690 owner I might be wrong. So do your own research and hopefully some 790 owners can advise you better. Perhaps you could ask on the link I just provided as well.

UPDATE - my 0806 and 0809 comments relate to the Apex, not the Hero. Apologies. The comments might still stand, but this is why it's important to check yourself. There are so many models and BIOS releases!

[Luis00014]

JohnAb wrote:
If you want to try some of the other 08xx BIOS versions, you can find them in this thread: https://www.overclock.net/threads/official-asus-strix-maximus-z790-owners-thread.1800191/page-85

Right then, if 0813 is not working for you and you cannot downgrade to 07xx, then perhaps you could try 0806 or 0809, only because iBruceypoo had good experiences with them... but remember that they are not 'official' in the sense that they are not on the support page. However, I believe they are made available by Shamino as 'release candidate versions' to try at your own risk. He works for ASUS and is on the BIOS team. I'm not recommending you do this of course, just trying to give you options. Your choice of course and as a humble 690 owner I might be wrong. So do your own research and hopefully some 790 owners can advise you better. Perhaps you could ask on the link I just provided as well.

UPDATE - my 0806 and 0809 comments relate to the Apex, not the Hero. Apologies. The comments might still stand, but this is why it's important to check yourself. There are so many models and BIOS releases!

The 0809 bios version on that link you gave is for the Maximus Z790 Apex. Does it also work for the Z790 hero mobo?

On the Asus site the rollback bios version prior to this one is 0703 and when i try to use it with easy flashback it says "selected file is not a proper bios" and doesn't allow it's installation.

Trying to manually flashback the bios now.

[JohnAb]

Luis00014 wrote:
The 0809 bios version on that link you gave is for the Maximus Z790 Apex. Does it also work for the Z790 hero mobo?

On the Asus site the rollback bios version prior to this one is 0703 and when i try to use it with easy flashback it says "selected file is not a proper bios" and doesn't allow it's installation.

Trying to manually flashback the bios now.

Oh, sorry. Not sure. I was simply trying to be helpful.... perhaps there are other threads with what you need.

[Tron64]

Tron64 wrote:
Is it possible to downgrade BIOS from 0813 to 0703?

So it's not possible to downgrade? Any ideas?

[iBruceypoo]

Tron64 wrote:
So it's not possible to downgrade? Any ideas?

It's always possible to install another bios be it earlier version or the latest.

0813 is known good.

I would attempt to reinstall 0813 once again make a 2nd attempt.

I always use the EZ Flash Tool within bios to reflash a different bios, so far it's 100% successful even when the new experimental bios was not as good.

Hope this helps out. 🙂

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If you think your primary bios is corrupted then switch to the 2ndary bios chip on your board and proceed.