Precision T7910 LSI SAS RAID controller not initializing

The Dell Precision Optimizer ran the other night and installed something which I didn’t take note of- when I restarted my machine the usual Dell logo was displayed but before the usual messages about initializing the controller and showing the drives it stopped and displayed “Alert! Hard Drive not found” then gave options to retry, run bios setup or run diagnostics.

I ran the diagnostics which was all fine except for the missing drive problem. I also checked all the drives and connections but it still got stuck at the same place when attempting to boot.

I then removed the boot drive and connected it in a usb drive caddy and was able to boot from there, albeit in Safe Mode, but I guess that may be a limitation of the drive partition layout and usb interface. The fact is the drive is still bootable so the issue seems to be with the LSI SAS raid controller.

Any ideas on how I go about fixing this or do I need to get another pci raid controller card and connect that to the back plane instead? The boot drive is an ssd and I have another ssd (neither are raided) and a mirrored pair of hard drives in the four 3.5 inch front bays.

I’m just a few months out of warranty and can’t get any help from Dell support so any help would be appreciated.