BOOT QLED when using two PSUs

[Alpha Stigma]

Hello, i've been trouble shooting getting my first rig to work with multiple GPUs (i can run two atm). When i run two GPUS+risers & mobo off one PSU it boots fine. When i power my Mobo & GPU1+Riser with one PSU and GPU2+riser with the other PSU (in order to test if this will work when i have more GPUs) i get a BOOT QLED on my mobo and it wont post. I currently only have enough PCIE cables to run two cards along, i'm waiting for splitters to arrive tonight/tomorrow, hence why i'm testing two PSUs with only the two GPUs.

I hope i didn't explain this poorly . Any help is appreciated, hardware listed below.

Hardware
B450F II Mobo
Ryzen 3 3300 CPU
Inland M.2 SSD
16gb Gskill DDR4
Parallel miner 1200W (900W) server PSU and breakout board
Gskill 850W PSU
3x 6700XT
1x 6600XT
1x 3080 Ti

Thank you

[1714827399]

1714827399

[philipma1957]

this is the BTC section not the gpu section.

I asked mods to move this to alt coins

[Alpha Stigma]

Sorry, i thought i posted in the hardware section. Thank you

[FP91G]

Gskill 850W PSU works as a main power supply unit and there are no problems with it if you connect 2 video cards and a motherboard?
How do you synchronize the startup with the server power supply?
Do you have an 8-pin and 24-pin adapter on the server power supply for powering the motherboard?

[adaseb]

The proper way to run 2 PSU at the same time is to make sure they are grounded together somewhere and make sure you are not sharing any 12V rails between the PSUs, or else you will blow one up. Basically if 1 GPU requires 2 PCIe connectors make sure they are connected to the same PSU not from one of each because you will get a current feedback loop.

Next is you need to get a paper clip and short those 2 pins so the PSU will turn on. Forgot which ones they are so just google it.

Then what you do is start them both at the same time, if you start one too early or late it won’t detect all the GPUs. Also maybe attach a fan or 2 so the second PSU doesn’t run without a load which can also damage the PSU.

Good luck.

[Alpha Stigma]

Gskill 850W PSU works as a main power supply unit and there are no problems with it if you connect 2 video cards and a motherboard?
How do you synchronize the startup with the server power supply?
Do you have an 8-pin and 24-pin adapter on the server power supply for powering the motherboard?

Yup i have those adapters.

I've (likey) ruled out the power supplies as the issue. I've tested...

1) PSU1 powering the Mobo + risers and PSU2 powering the GPUS
2) PSU2 powering the Mobo + risers and PSU2 powering the GPUS

in both cases the rig will boot with one GPU but not two...

[Alpha Stigma]

The proper way to run 2 PSU at the same time is to make sure they are grounded together somewhere and make sure you are not sharing any 12V rails between the PSUs, or else you will blow one up. Basically if 1 GPU requires 2 PCIe connectors make sure they are connected to the same PSU not from one of each because you will get a current feedback loop.

Next is you need to get a paper clip and short those 2 pins so the PSU will turn on. Forgot which ones they are so just google it.

Then what you do is start them both at the same time, if you start one too early or late it won’t detect all the GPUs. Also maybe attach a fan or 2 so the second PSU doesn’t run without a load which can also damage the PSU.

Good luck.

I haven't mixed the PSUs as far as powering the GPUs, just the GPU and riser mix, but after getting a new PSU and splitters to test all the configurations i think i've ruled out the PSU as the cause... I have the ATX PSU triggering the server PSU via molex.

1) PSU1 powering the Mobo + risers and PSU2 powering the GPUS
2) PSU2 powering the Mobo + risers and PSU2 powering the GPUS

in both cases the rig will boot with one GPU but not two...

I'll try to reinstall windows as a last ditch effort. I'm considering returning the Mobo and trying another...

[Alpha Stigma]

Update: Reinstalling Windows fixed everything...