Is fast boot (or rapid start, etc.) enabled?  Or is there an administrator password on Setup (press F2 multiple times immediately after power on to see if you can get into Setup).

Connect the monitor to another gpu port

@ejn63​ Hi. Thanks for the suggestions. The fast boot option is disabled.

mazzinia_ Hi. Thanks for the suggestions. Strangely I have tried all ports via the display port. None worked.

I had initially thought that it was due to the primary video output setting being messed up. But it transpired that it was set to auto - default setting.

I managed to sort it out by connecting my monitor via the HDMI cable with the display port connector. Very storage indeed, but it worked. So, it appears as though the culprit is the monitor. 

But what's strange is that I have another motherboard which works absolutely fine with the display port. I can see the Dell Logo and enter bios etc. during booting. 

Any ideas why two 5820 motherboards would behave differently. BIOS settings? 

Thanks for all your help. 

@simss​ there are 2 different versions of motherboards for the 5820. One for the xeon cpus. And one for the normal intel cpus.

Maybe one of your 5820 has a xeon and the other has an i9 ?

@mazzinia_​ Yes, that's right. However, the ones I have support Xeon CPUs. Both work with Xeons. I suspect that I wouldn't be able to install the Xeon CPU into the convention Intel motherboard as the socket is different?

The reason why I have two 5820 motherboards is that I ended up buying a replacement for the original which was intermittently getting into the Safe Mode (2 amber - 2 white error).

Although after taking it completely out and reinstalling seem to solve the issue. Perhaps it was a loose connection etc? 

@simss​ that's correct, you would not be able to install

uhm... sounds more like it had some short circuit that got solved by being reinstalled. Is this mb, the one with the display quirk ?