Why can't I start my PC with one of the video cards?

Question

Iron

Current build:
MB: Pro WS WRX80E-SAGE SE WIFI
CPU: Ryzen Threadripper PRO 3995WX
RAM: G.Skill F4-3600C18D-64GTRS (8x32 GB)
PSU: Corsair AX1600i
Video: ROG-STRIX-RTX3090-O24G-GUNDAM (4 pcs) ) (ASUS)

To eliminate unnecessary - turn off the screws, leave one memory, leave one video card.
Does not turn on with qcode 94
error. If you disconnect the DP and HDMI wires, qcode will report AA and the PC will supposedly boot, but the image cannot be obtained.
If you activate the integrated video card and boot with it, then 3090 is not visible in the system.
The current 3090 has 3 connectorsadd. nutrition. If you install the ZOTAC RTX 3090 Trinity version, the system starts correctly. ZOTAC has 2 connectors . nutrition. Everything that is possible is connected to the motherboard. Add. power on PCI-ex, etc. Once it started with ASUS 3090, but the resolution was 1024 * 768, then it stopped altogether.
Is it worth paying attention to the fact that the memory requires 1.35 Volts and has a 3666 bus, and only similar memory is indicated in the MP specification, but 1.2 Volts and 2666. Although they write on the Internet that it already works with 3200. But everything starts with 3090 from ZOTAC. 3090 from ASUS 4 pieces, tried different ones - the effect is the same.
BIOS updated.

Small notes on qcode:

Reset, no display cables - QC=AA
Cold boot, DP connected - QC=94
Clear CMOS, DP connected - QC=94
Cold boot, no GPU power connectors, DP connected - QC=02
Cold boot, HDMI connected - QC=62

Related links:
List of supported MP hardware: https://www.asus.com/en/Motherboards-Components/Mo...
Target graphics card that does not start: https://www.techpowerup.com/gpu-specs/ asus-rog-str...
Graphics card starting normally: https://www.techpowerup.com/gpu-specs/zotac-rtx-30...
Power supply: https://www.corsair.com/us/ en/Categories/Products/...
Processor: https://www.amd.com/en/products/cpu/amd-ryzen-thre...
Memory: https://www.gskill.com/product/165 /299/1582267800/...

Answer 1

Well, logically.
Either the vidyakha is dead, or it does not take out the PSU