DeckLink Mini Monitor - no output

I use the Mini Monitor to output videos, pictures and other media to ATEM TVS using the SDI and to a large TV in the studio using the HDMI. I decided to move the Mini Monitor to another computer, so it will be more comfortable for work.

I bought HP 8200 Elite SFF with Core i5-2500 quadcore CPU, 4 GB DDR3 and integrated Intel video card. The machine was with Windows 7 pro and I upgraded it to Windows 10. Installed the Mini Monitor in this machine and checked the device manager - everything seems to be just fine. Moved my Wirecast license on the same machine and configured it the same way as it is on the main machine it was working.

When I start the output, the CPU usage rises to 55-65%, but all I can see on my multiview and the TV is just black screen. I've tried with different versions of BMD Desktop Video and drivers, but I get the same result.

Does anyone have any idea where the problem could be and how to fix it?

Six days ago I wrote to the support and still no answer.
No any posts here too. Am I the only one with such problem!?

Which version of the Desktop Video driver are you using? This could be the culprit. Use the Blackmagic Media Express application to troubleshoot the monitor, and once that works, you can verify that the monitor, cable, card, and system are all working correctly.

Note that this is just user-driven support here -- BMD only occasionally visits these forums. For real support, you have to contact them via the website or by telephone.

I've tried with 10.5.2, 10.5.4, 10.6 and 10.6.4. On this computer the card does not work with neither of those versions. On the other computer it works with all of them... That's why I think that the problem maybe is the computer, but I have no idea. The tech cpesc of the card say only that PCIe slot is needed and nothing about the CPU, RAM and video card... I wrote to the support email one week ago, than one more time two days ago and still have no answer...

If it was me I would make sure my BIOS was on the latest one available for the machine, then look to see if there are any PCI-e power setting in the BIOS and change them to the opposite, so it it's set to auto try disabling it or if it's disabled try turning it on

Also if it gives options in the BIOS for the PCI-e socket then try changing those, so if it is set to PCI-e 3 try setting it to 1 or 2, also if it gives options to change the PCI-e from a 16x slot to a 1x slot try setting it to that.

HP are notorious for locking down things in the BIOS so cards don't work properly until you change some of the settings. Unfortunately I can't seem to find an online manual for the BIOS so I can't say if it has these settings or not or what they are set to.

When you look in 'Device manager' under 'Sound, video & game controllers' what BM devices show up?

If you play back a supported file with the correct frame-size/frame-rate in Media Express do you also get a black output on the TV?

How long is the HDMI cable going to the TV?