Can't get my mac mini late 2012 to boot

[daddie05]

Hello fellow members. I am creating my first thread hoping you guys can help me out here. I decided to replace my hard drive with one that was an external 2.5 hdd. After completing the switch, I went to boot my mac mini with my bootable mountain lion usb/disk and only the bootable usb showed up. When I go to click the bootable disk, it gives the white screen with the prohibited sign instead of the apple sign. If I let it boot without holding the option key, then it gives me a folder with a question mark.

I tested it on my mbp, and it shows my external, Mac hard drive, and the bootable usb. What is happening here? Did I mess my mini up?

*created my bootable with lion disk maker

Thanks in advance.

 

[cinealta]

Sounds like OSX may not have been installed properly on the external 2.5 HDD. Did you try booting from it externally to the Mini? Is it formatted properly? Why not boot from the Mountain Lion USB flash drive, go to Disk Utilities and reinstall OSX onto the 2.5 HDD while it's in the Mini?

 

[daddie05]

Sounds like OSX may not have been installed properly on the external 2.5 HDD. Did you try booting from it externally to the Mini? Is it formatted properly? Why not boot from the Mountain Lion USB flash drive, go to Disk Utilities and reinstall OSX onto the 2.5 HDD while it's in the Mini?

Thanks for the reply. The external (now internal hdd) does not have an os. Therefore, it is not formatted for mac. I did the guid partition thing to a 500gb ext hdd i had and I just installed osx m. lion successfully.
I think I will maybe try and do the same with the new internal hard drive and hope it works.

When I try to boot from the mountain lion usb I get the prohibited sign (that is when I only have the m. lion usb connected).

 

[for this]

What version of ML do you have? I think the minimum is 10.8.1 which was the version the 2012 Mac mini originally shipped with.

Also try resetting PRAM. I used to turn off the mini halfway while installing Mavericks (to snatch the ESD disk image), doing that messed up the PRAM and prevented my mini from re-installing.

 

[daddie05]

Thanks for the replies guys/gals. I Figured it out after installing the OSX with an external formatted with the Guid partition. I booted into the the the external OS and formatted the internal that I swapped out the same way I did the external hdd and all is well. I thought I had messed something up and the Mac mini was a paper weight.

My computer crashed after updating it from ML 10.8.3 to the new Yosemeti 10.10.1. I updated to Yosemeti last night, and this morning while I was installing all my needed software and inputting my email accounts it just shut off/crashed. I hope it is just issues with the OS and not my mini.

Thanks again for all the help.