Linux Mint 18.3: Why won't it boot?

Question

linux

The problem is this: the desktop was in the process of migrating from Windows to Linux Mint and the disk structure was as follows:
sda (SSD, /, ext4)
sdd (HDD, /home, ext4)
sdb (HDD, /media1, ntfs)
sdc (HDD, / media2, ntfs).
Further, on sdb and sdd, I created two ext4 partitions each and assembled RAID10 /dev/md127 from them like this:
/dev/sdb1 /dev/sdc2 /dev/sdb2 /dev/sdc1 (perhaps I indicated the order incorrectly). The array was assembled, synchronized.
Now, when I turn on the computer after the BIOS screens, I see a black screen with a blinking cursor, no diagnostic messages.
BUT! If you choose to force boot from the SSD, the system boots as if nothing had happened.
I guess the problem is with the bootloader (was it really on one of the disks with NTFS partitions?). How would you recommend doing it?

Answer 1

Register the correct bootloader