No VGA signal on POST with brand new RTX 4080 S

[Yurikane]

Hello everyone,
I'm a bit desesperate so i try to find new angle to solve my issue.
I recently bought a 4080 Super FE but it never pass VGA post.

My system :
CPU : 5800x3D
MB : B450 tomahawk max
Ram : 32Go RAM 3200
PSU : Corsair TX750M
GPU : 4080S previous one > 6950XT so about the same power usage

What i have tried so far :
- Bios : update to the most recent one / Switch between UEFI to UEFI+Legacy / Force Pcie3
- Clear Cmos
- Reseating cables multiple time / Try different one in different slot from PSU
- Connect with HDMI / DP on 3 differents screens
- Clear in safe mode previous drivers multiple times with DDU and AMD clean up utilities

Whatever i have done, i never had access to Bios or windows with the new card. I can boot with no issue with a really old one : ATI HD 4870
When i power on with the RTX, both of its fans are working correctly , the LED Geforce RTX are white so nothing particular but it had never pass a single time VGA post. I can't test right now the GPU on other setup, i will try tommorow.

If you have any suggestion, you are welcome and thanx you by advance for your time. I'm sorry for my terrible english.

 

[Double-Click]

Did you check the OSD menu for the input on the monitor?
I had the same issue years ago and wound up having to manually set it to DP after using HDMI previously.

 

[Vya Domus]

I know some of these 40 series cards had issues on AM4/AM5, is there an explicit mention of 40 series compatibility in any of the BIOS update notes ? It may be that this board never got updated with those fixes.

I am pretty sure it's a BIOS incompatibility issue but only trying it in another system would rule out the card being DOA.

 

[Zach_01]

What are the 4080S power connector requirements?
I know it’s a 320W rated GPU (FE) but what about the power connectors?