DOS ain't dead

Hi,
it was the first time for me to have a computer death simply by modifying BIOS changes (no firmware update). I installed a new Samsung NVMe HD, copied the system from the old SSD on it with Samsung Magician (yes it can copy an old bootable system to a new HD, was new for me too). Then I wanted to create a multiboot system Win - Linux with grub, this didn't work so I modified some BIOS settings (TPM, trusted platform module, CSM, boot order etc.). It didn't work as expected, so I decided to use the old HD for vm images.
After a reboot I changed the BIOS settings back (assume, problem was that I did not create new keys for TPM or something like this). Reboot - and NOTHING worked, except fan. No BIOS, nothing.
Long story, short result:
The BIOS was dead and after a long while of rtfm I found the solution for the Gigabyte mainboard that I have never seen before (and I thought I know them all):
Download the BIOS from internet, copy it on an empty USB-stick and rename it GIGABYTE.bin (this was hard to find).
Then switch OFF the machine, do not remove power cable and do not switch off the power switch on the back side of power supply, plug the stick into a SPECIAL PREPARED USB port (see manual). Gigabyte has a mini switch on the mainboard, press it and it updates the firmware without Win/Linux/DOS and no GUI. The only thing you can see is a blinking LED on the mainboard. Wait, and after a few minutes everything works again.

Sorry for this off topic article, but I hope it can help any hobbyist out there.

All this that you have told is very interesting. Thank you very much Fritz

> All this that you have told is very interesting. Thank you very much Fritz
>

I also have a Gigabyte Board. Hope I never need your advice, Fritz

Doesn't this MB has DualBIOS? If so, there are (also not much known) key combos to copy/swap main/backup bios that may be helpful in such cases. And did you tried reset CMOS first?

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DOS gives me freedom to unlimited HW access.

> I
> modified some BIOS settings (TPM, trusted platform module, CSM, boot order
> etc.).
...
> After a reboot I changed the BIOS settings back (assume, problem was that I
> did not create new keys for TPM or something like this). Reboot - and
> NOTHING worked, except fan. No BIOS, nothing.

Future of technology is amazing.
But we choose most ugly from all possible.

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Make DOS great again!

Carthago delenda est, Ceterum censeo Carthaginem delendam esse.

Just to clarify, the machine was really dead:
- no bootup beep,
- monitor was black, no blinking cursor, nothing, only fan worked,
- adding a BIOS reset jumper for a few seconds only stopped the fans, nothing else,
- no Dual BIOS option (at least I found none)
- replacing the whole removable hardware (HD, RAM, graphics card etc.) by known good hardware changed nothing.

Manual only says the following:
18) QFLASH_PLUS (Q-Flash Plus Button)
Q-Flash Plus allows you to update the BIOS when your system is off (S5 shutdown state). Save the latest
BIOS on a USB thumb drive and plug it into the Q-Flash Plus port, and then you can now flash the BIOS
automatically by simply pressing the Q-Flash Plus button. The QFLED will flash when the BIOS matching
and flashing activities start and will stop flashing when the main BIOS flashing is complete.
see: https://download.gigabyte.com/FileList/Manual/mb_manual_b550m-ds3h-ac_e_1401.pdf
Thats all.
If you have a closer look in internet you will find articles that say that the Q-Flash port is a white marked USB port on the mainboard.