HP Z820 Workstation blank screen on power up

[Dave74one]

I recently got a Z820 workstation with dual CPU's. I put an SSD hard drive in it and booted it up and got it to boot tinto Windows 10. I shut it down and tried to add more memory and ever since it has not booted to Windows. 

I currently have all the black DIMM slots filled with 4GB PC3 12800 sticks. I have a BARCO MXRT 5400 video card(came with the system) in slot J41. The SSD hard drive is in Bay 0. 

I have tried the solutions about the BIOS update but I can't get the system to recognize my USB keyboard to press f10. I have tried removing the CMOS battery and leaving out for hours. I have tried pressing the CMOS reset button for 5 seconds then the power button for 5 with the tower unplugged.

I am thinking it is a simple configuration issue with maybe memory or how the hard drive is plugged in. there is not really a good manual that explains what the initial config was. 

Thank you for your help with this.

[Lil_Boy_Blue]

Hi

This is gonna hurt...

Stating the bleedin' obvious is what I majored in.

https://support.hp.com/us-en/product/hp-z820-workstation/5225041

How close to the previous state can you get?

https://support.hp.com/us-en/document/c02693833

• Turn off the computer, and then connect the power cord.
• Press and hold the Windows key and the B key at the same time, and then press and hold the power button for 2 to 3 seconds.
• Release the Power button but continue pressing the Windows and B keys. You might hear a series of beeps.
  The HP BIOS Update screen displays and the recovery begins automatically. Follow any on-screen prompts to continue the startup to complete the recovery.

[Dave74one]

I have looked at the first link. I read through the screen being blank and other posts that are archived about putting the BIOS on a USB and attempting to update it that way. I can remove the memory and it gives me 8 beeps and flashes. I will let you know if the WIndows key + B key works. It doesn't seem like it recognizes the keyboard. I even tried the PS/2 to USB adapter.