HP Desktop "Baker" motherboard bricked after BIOS upgrade to 3.8

[Dansk_Kunde]

Upgraded my sons computer BIOS last night to version 3.8 (as I believe it said onscreen) since it popped up in HP Assistant software.
UEFI upgrade from within windows apparently went fine (updating 4096 blocks), lead to restart and again updating some 1200 blocks. Second restart lead to BIOS can't post... 🙄
The computer have following upgrades:
RAM replaced with 32GB, RTX2060 6GB GFX Card replaced with Asus Dual RTX4060 TI 8GB, added 1TB Samsung SATA SSD. All has been running flawlessly till said BIOS upgrade.
Symptoms when power on: 
There are no sounds and no video signal (HDMI/DP) via dedicated GFX card (CPU has no GFX). 
CPU fan and chassis fan spins. GPU fans constantly gets a very short slow spin at a about 15 second interval. There is constant light in power button and chassis front, but no light at all in keyboard or mouse.
Actions already taken:
Disconnected all peripherals except HDMI connected screen, mouse and Keyboard. Tried WIN+B power button sequence to restore BIOS - nothing happens. Tried to pull CMOS battery and set both CLEAR CMOS and PW jumpers - which required to reseat GFX card so that is also tested. Even tried an old GFX card I had laying around which does not require PCIE power cable.
Reinstalled original 16GB RAM, so RAM has also been reseated. Disconnected extra SATA SSD. Still BIOS does not post.
Reassembled with new components (RAM, GFX, SSD) and of course still no BIOS post.

Any help would be greatly appreciated 

[Paul_Tikkanen]

First make the USB flash BIOS recovery drive on another PC from the file.

Watch the video just up to where the BIOS recovery flash drive has been created.

On another PC you will only have the option to create the USB BIOS recovery drive.

Updating the BIOS on HP Consumer Desktops outside of Windows 11| HP Computers| HP Support (youtube.c...

This is the latest BIOS update file HP has for your PC:

HP Pavilion Gaming - TG01-1425no Software and Driver Details

I just created one for the PC you have on my Dell Optiplex 7050 PC, so I know this part will work.

After you create the USB BIOS recovery drive, follow the instructions that show up after the USB recovery drive has been successfully created.

1. Power off the device to be recovered.

2. Insert the USB flash drive into a USB port.

3. Power on the device.

4. The device may reboot up to 3 times with indicator lights on the keyboard flashing, or the screen appearing blank for short time.

Hopefully, that will fix the problem for you.

If that doesn't work, try making a recovery drive with the previous BIOS version:

https://ftp.hp.com/pub/softpaq/sp149001-149500/sp149470.exe 

That would be the only suggestion I can offer.