Precision 5820 U.2 Backplane

Hi all

I've had a Precision 5820 with the Xeon W-2195 CPU for a few years which did not ship with the FlexBay NVMe/U.2 backplane, just SATA.

I've managed to get hold of a couple of NVMe/U2 backplanes and cables from eBay at a price cheaper than getting them from China, which i'd prefer not to do anyway.

I *presume* the backplanes were stripped out of a non-Xeon 5820 as one of the U2 ports was covered with a yellow 'Do not plug in' label due to less PCIe lanes on the non-Xeon models, hence I've removed the label, which has now allowed me to connect both cables to the backplane (temp sensor cable was also included).

I've removed the SATA backplane from the top 2 drive bays and installed the NVMe U2 backplane, it's been connected to the power cable and the 2 mini-SAS cables plugged into the motherboard, all good so far.

However, when I turn on the 5820, the status light on the top 2 drive bays flashes yellow when they are populated, I've tried only inserting one of the disks, removing one of the cables from the motherboard. 

The disks are not recognised in BIOS and obviously neither by the Windows 10 Operating system. I must add that I have not yet obtained the U.2 NVMe disks and have been testing with a 12TB Spinning disk and a 1TB SSD as I understand that the U.2 connector is backward compatible with the SATA interface.

Does anyone have any idea what is wrong?

Kind Regards