Dell Optiplex 9030 HD issue

I have a Dell Optiplex 9030 that has been running A-OK for the past year, but recently it throws a message that the HD cannot be found.  This appears like a POST message, but it actually occurs even when Windows is running, then of course I must reboot, and all is OK again...until it happens again.  This occurs 3-4 times per week with daily use.

I replaced the original HD with a SSD when I purchased the unit, and installed a fresh copy of Windows 10 Pro, so don't know if it may be a SSD issue or a mobo issue.  Anyone have any advice?  

Thanks.

Ron