Won't boot with second internal HDD

[tchap1]

The machine won't boot with second internal HDD after it has been formatted and ran Time Machine for backup. Hangs at "Loading operating system" message. Can hotplug and recognizes fine.

 

[wlp5]

it has been formatted and ran Time Machine for backup

not really sure about the meaning of this statement but have you checked the hard disk boot priority in the bios ?

 

[tchap1]

sorry I can be more clear--I attached the "raw" drive and booted up as usual. OSX recognized the drive and I formatted it in the customary fashion. I then had a backup disk for Time Machine to use and created backups per the default TM schedule. However when rebooting, the machine hangs at the "Loading OS" part. Hotplugging means I can plug in the second SATA drive (after unplugging and booting up as usual) while the machine is on and it recognizes it as always.

 

[humph]

.... Hangs at "Loading operating system" message..

Sounds like the PC is trying to boot off a non-botable drive.
ie: that the "2nd" drive (TM backup) is being "booted", as it's perhaps on port 0 versus your main drive being on port 1.

Hit F12 on powerup, and select the "main" drive to boot from (with both connected).
If all well, then just change the HD boot order in BIOS (or swop cables over).

 

[tchap1]

SOLVED Re: Won't boot with second internal HDD

Yes boot order was the issue. Am used to Windows auto-assignment of OS partition as boot disk. Thanks.