had been working 100% for a while, but now I've my SATA disks

[bitguru]

had been working 100% for a while, but now I've lost my SATA disks

I built the system described in my signature about four years ago. I had it working 100%, no problems with audio, video, network, sleep. This was, I think, running X.6.

Then lately I tried upgrading to X.10 (Yosemite) and a newer MultiBeast. I had it working, mostly, for a couple of weeks, but then I somehow lost my SATA disks. The BIOS identifies them at boot but attempting to boot from the disk fails, and when I boot to the X.10 installer on a USB thumb drive then Disk Utility can't see them either.
At first I thought maybe the disk went bad but I don't think that's the case, because when I attach an eSATA extarnal drive the BIOS does identify it (along with the others) but the X.10 installer can't see it either.

Could I have inadvertently messed up a BIOS setting? Maybe I did something wrong when installing MultiBeast?? Does anyone have any ideas? Would updating the mainboard's firmware be likely to help??

 

[neilhart]

Go in to your BIOS setup and see if the SATA devices are still set to AHCI. If they are not, set them to AHCI, save and reboot.

Good modding,
neil

 

[bitguru]

That seems to have been the issue, thanks. I can't imagine how the setting could have departed from AHCI, but it did.