like the title says. I get a black screen with a nonblinking underscore on the top left corner of the screen when i turn on the system but if i plug the sata cable of my secondary hdd into a different port of all 6, the system boots up windows 10 normally. I tried updating the bios, reinstalling windows, uninstalling the sata drivers and set the disk storage to AHCI but still get the same black screen. The only solution i have found is plugging the sata cable into another port and then the system will boot otherwise i get the infinite black screen and no boot cant even get to the bios. I think the problem is the motherboard but im not sure. I dont want to buy another one if i can fix this one. help please!