Hello, problem with my DH87MC board. I have changed Legacy Bios to UEFI and disabled legacy support, now no screen on start. When OS ist loaded screen working fine. What the error ? Have disabled Intel Video adapter and use PCI-E x16 XFX 5830 1gb Card. How access BIOS ? Windows 8.1 bootloader are converted from legacy to UEFI.
Aleksandr, you may want to try the following troubleshooting provided by a customer in the following thread. /thread/44769 https://communities.intel.com/thread/44769
We were able to replicate every step on our system, at the end after 8 to 10 hours without the CMOS battery, we turned ON the system and we were able to access BIOS and reset default settings.
If these recommendations worked for you, I would suggest you keep the integrated graphics "enable" while we got this issue fixed.
We are still waiting for a solution and unfortunately I don't have an ETA to provide you.
This thread is related to the same issue but on the DH87RL motherboard /thread/44789?start=30&tstart=0 https://communities.intel.com/thread/44789?start=30&tstart=0