Help: grub2 -to- firmware interface issue

[Dr. George E. Moore]

I have a Dell Precision 690 with four (4) SATA hard drives. Prior to a 
disk crash, I had no problem with BIOS/grub recognizing each drive. 
After removing the drive and rebuilding the kernel, grub now only 
recognizes one disk, even though BIOS acknowledges the presence of four.

Re-installing grub2 and updating grub (update-grub) has no impact; nor 
does switching between the AHCI and SAS controllers in the BIOS work.

Could someone explain why this is happening and/or how to correct this 
problem.

Thanks,