Monitor unable to detect computer after hardware install of NVS 310

[klint01]

I am trying to install a new graphics card (NVIDIA NVS 310) to the HP computer.  The Motherboard is MS 7826 version 1, which has onboard dual DVI output.

I followed directions for installing video card: https://support.hp.com/us-en/document/c00007413

That didn't work!  After installing the graphics card and starting the computer, I get nothing on the monitor, not even BIOS screen.  So I am unable to disable the onboard video via BIOS with the graphics card installed.

I tried troubleshoot with https://h30434.www3.hp.com/t5/Desktop-Video-Display-and-Touch/Graphic-Card-Monitor-No-display-Signal... 

I even had the PC powered off, unplugged, graphics card installed and did a CMOS clear.  Turned PC on and no display on the monitor.

I double checked by DisplayPort cable is backwards compatible, which it is DP 1.4 and the card is DP 1.2.

The only way I can get a display, is to remove the graphics card and use the onboard DVI display.  I don't know what else to do?

[klint01]

Additional information.  I validated that the DisplayPort cable is plugged into DP 1 of the graphics card and properly connected to the monitor (DELL U2717D).  On the DELL, I also toggled the DP support between DP1.2 and DP1.1a.  Neither option works.

So still unable to get a monitor image (DP or DVI/HDMI) when the NVS 310 graphics card is installed on the motherboard.