Question New PSU Wont start with GPU installed.

[hellshound38]

Having this Issue I just can't figure out. I have a working system with ASROCK z690 motherboard a 750w corsair PSU and 2080 rtx. I bought a 4090 and and FSP Hydro Pro TI 1000 as an upgrade.

If I put the 1000w and 4090 in the computer won't start. The motherboard lights up when its plugged in, and when I press power everything flashes and fans spin in the PSU for less then a second and it stops and turns off.

I have tried everything I could think of and would appreciate advice. Going a little crazy here.

Things I have tried-
1. Replace the FSP 1000w, identical version same issue.
2. If I remove the GPU it boots fine.
3. The FSP 1000w wont boot when plugged into the 2080 either, using a 6 and 8 ping ATX.
4. Putting everything back the 2080 and 750w still boot fine.
5. Tried a CMOS clear
6. Yes I change the cables every time to the ones that come with each PSU.
7. Tried 4x 8 pin ATX instead of 12 pin on the 4090.
8. Tried a different wall outlet with nothing else plugged into it.
9. Tried disconnecting everything non essential.
10. Tried a different PCIE slot.
11. Tried different combinations of cables and slots on the modular PSU.

I just can't fathom why it won't boot with Either GPU installed, but the old setup still works fine.

 

[DRagor]

The motherboard lights up when its plugged in, and when I press power everything flashes and fans spin in the PSU for less then a second and it stops and turns off.

This is clear sign one of PSU protections kicks in and shuts it down. Since it happens with both GPUs we can rule out bad GPU. Either the PSU is bad or you are connecting some of its cables incorrectly. If you tried 2 FSP then more likely the latter.

 

[hellshound38]

What cable could I be connecting wrong ? It boots fine without a GPU, which seems to imply the CPU and Motherboard cables are fine. The new GPU only requires the 12v atx3.0 cable. There is only 1 slot for it.

The only thing I could think of is the PSU protections are just not compatible with the draw from the motherboard with the GPU installed. I ordered a different PSU to try, but I really wanted to use this one.

 

[DRagor]

I don't see a way a motherboard that works fine with other PSU would somehow be at fault here. So in either case fault must be at PSU side.

 

[hellshound38]

Just to update. Got an MSI mpg 1000w with the atx 3.0 cable and it works.

So frustrating

 

[DRagor]

Just to update. Got an MSI mpg 1000w with the atx 3.0 cable and it works.

So frustrating

Well, happens. Recently amount of problems with new, fresh from shop hardware has been greatly increased. Quality control seems to be going in wrong direction lately. Not to mention things that should be compatible by default but are not for no good (or even reasonable) reason.

 

[rcald2000]

hellshound38 Please update your motherboard BIOS to the latest non-beta version and then retest your RTX 4090.​

Question: Which Asrock Z690 motherboard do you have, and was was the BIOS version before updating it, per my suggestion?

Addendum: Disregard above. I somehow missed your update about the MSI mpg 1000w. Glad that it all worked out for you in the end.