A technician receives an error message when trying to boot the server stating the operating system was not found. Change management logs indicate a new hard drive backplane was installed in the…

Checking system board cables is the correct first step because installing a new hard drive backplane could have displaced or loosened data and power cables connecting the drives to the system board. An improperly seated or disconnected cable would prevent the BIOS from detecting the boot drive, causing the OS-not-found error. This follows the troubleshooting principle of verifying the simplest physical cause before escalating to software or destructive remediation.

Rebuilding the RAID array is premature - you cannot confirm array integrity or necessity until the physical connection issue is ruled out.

Reinstalling the OS is a destructive and time-consuming step that should only be attempted after all hardware and configuration causes are eliminated.

Removing the newly installed hardware is a valid rollback step, but checking cable connections first is less disruptive and may resolve the issue without undoing the change.