Please Help new drive works as external, not as internal

[AceMason]

If anyone can help with this issue I will be so grateful; I've spent hours trying to figure this out.

Basically, my friend upgraded the internal hard drive in his MacBook Pro from 250GB to 500GB, formatted it using his iMac (Mac OS Journaled), and installed Mavericks on it. The hard drive is a Toshiba MQ01ABD050 500GB.

When he installed it into his MacBook Pro, Mavericks doesn't boot, it only shows a blinking folder with a question mark. I thought it might be something with the hard drive cable so I bought a replacement and tested it but it still gives me a blinking folder with a question mark.

I then put in the hard drive from another Macbook Pro into my friend's MacBook Pro and it worked.

I'm not sure why the new hard drive isn't working? Btw, when I use a SATA cable and plug the new hard drive in via USB it works perfectly.

tl;dr Macbook Pro hard drive works externally and OSX runs through USB but not internally.

Thanks for reading.

 

[Mac.User]

If you boot holding the Option key does it show the drive when its internal?

 

[AceMason]

If you boot holding the Option key does it show the drive when its internal?

Nope, it only shows a cursor and nothing appears.

 

[Mac.User]

If you replaced the cable, and the drive works externally, then it must be something on the board, or you knocked something loose when removing the drive.

 

[AceMason]

If you replaced the cable, and the drive works externally, then it must be something on the board, or you knocked something loose when removing the drive.

But when I use a different hard drive internally with OSX installed on it, it boots up. So doesn't that mean that the board is fine?

 

[Mac.User]

But when I use a different hard drive internally with OSX installed on it, it boots up. So doesn't that mean that the board is fine?

you had the drive via usb to the iMac when you installed OS X right? That may be your cause. You need to have the drive IN the mac then install OS X

 

[MackyMacs]

I have a very similar problem. Old Macbook pro. Bought new Western Digital Blue 2,5" 1TB hard drive. Connected with USB and installed fresh Mavericks on it. I have Snow Leopard on my old 500 Gb hard drive. I can boot from new hard drive with Mavericks on it if I hold down Alt key and select that drive when it's connected with USB. But when I unscrew the old hard drive from the machine and connect the new hard drive into the machine, it only shows the cursor on a grey screen and eventually a folder with ? question mark blinking.

If I reboot and hold down the alt key it won't find the system. If I connect the old hard drive with Snow Leopard with USB, it will find that system and start up from it. Then the new internal hard drive shows up as "not formatted".

Why do we have to install the system on the hard drive when it's inside the machine?

Any ideas?