Hello,
I am a generally-happy owner of the DZ77SL-50k motherboard with a PCIe graphics card used as the primary display adapter. A few days ago I attempted to enable General Optimisations in the BIOS boot configuration, as a result of which action the system has ceased to recognise the graphics card - and neither disabling this option nor even resetting the whole BIOS configuration to default values has helped. See below for more details. I will be very much obliged for any assistance with this, as I have pretty much run out of ideas.
More configuration details:
Originally BIOS video settings were "use the PCIe card as primary but keep internal graphics enabled", two DVI monitors connected to the external card and nothing connected to integrated HDMI (haven't got this two-card set-up working yet).
Exact symptoms:
After powering on the computer the computer produces the "two beeps, then two beeps" sound and blinks the power LED, while both monitors connected to the PCIe card remain in power-saving mode. The system then proceeds to boot and once video control has been passed from UEFI to the Linux kernel both PCIe monitors do come to life, although it seems the card is not in entirely normal state because X.org fails to detect it and therefore doesn't start.
If I connect a display to integrated HDMI while leaving the PCIe card that one shows nothing as well. It does work fine if I remove the PCIe card. Come to think of it, I had better check what happens if I leave the PCIe card in but force integrated graphics as primary in BIOS configuration.
If I switch the BIOS Configuration jumper to maintenance mode, the problem magically disappears - both PCIe displays come up the moment the system's powered up, no error beeps occur and and if I tell the system to boot, everything up to and including X.org starts up fine. However, switching back to normal mode makes the problem reappear.
Switching the jumper to recovery mode doesn't seem to help.
Let me know if you need any more information.