I had a SATA drive fail in a peculiar way. At first it was intermittent, but then it stopped working completely. The BIOS didn’t recognise it at all (yes, this is old gear). But when I plugged it into a USB enclosure I could read the data without problem. I cloned the main partition from the USB with Matrium Reflect and the cloned drive booted perfectly. It is still working fine. Can anyone explain more about this? How is it that the drive could not be read by the BIOS but could be perfectly cloned through the USB port?