HP Z440 PCIe slots acting weird

[Refurbeast]

Hello all,

The other day all of a sudden, my HP Z Turbo G2 stopping working on PCI slot 5 (x16). It was my NVMe boot drive. I'd get this error: "Hard disk - (3FO)"

After booting using an external NVMe adaptor and many experiments, I discovered that if I emptied out PCI slot 4 (x8), which had a blackmagic decklink mini playback video card, the HP Z turbo would work again. 

Then, when I put the decklink back on PCI slot 4, I get the same error again "Hard disk - (3FO)". However, if I put the decklink on PCI slot 3 (x4), the HP Z turbo works fine again. Except the decklink is not recognized.

Does anyone have a clue as to what may be happening?

Thanks in advance.

[BeemerBiker]

There are not enough resources to go around. Not sure if the bios supports it but see if you can specify GEN1 for all PCIe slots.  This is not just HP, happens mostly on mining systems..  If you have an x4 card put it into an x1 slots if the back of the connector is open to let it fit.

[Refurbeast]

After calling one of HP recommended service centers, they suggested taking out all other PCI devices to, in a process of elimination, try to identify if there was a faulty card. After doing that, all signs point to a faulty blackmagic decklink card. Will try a new one.