Motherboard ROG Z390 -f CPU9900kf, graphics evga1080ti overclocking, I skip the boot screen directly after boot into the system, I can't enter the BIOS, and then I will dig a motherboard battery, remounted, boot up, display is no signal, the mainboard boot VGA long light, but the connection of digital keyboard keys can be normal switch, and then I change the light machine card 1660 s everything is all right, so I use 1660 s into the BIOS opens the CSM and changing the 1080 ti, found that can enter the BIOS but can't enter the system shows invalid parttition table, then I restart enter BIOS on exit to choose the optimal configuration, this computer is also skip the boot screen into the system, I can't enter the BIOS and motherboard VGA the light has been on,,,, after I have been trying to find only open csm1080ti can enter the BIOS but the CSM can't enter the system, please bosses help me, bother me for a month