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Early 2011 model, A1278 / 2.3 GHz i5 or 2.7 GHz i7 processor.

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How can I install mac os on my new SSD drive?

My mac is getting old and slow, so I thought I'd give it an update. I bought 2x4GB Corsair macmemory and a Samsung evo 850 SSD. I formatted the drive and downloaded OS X El Capitan (since it is what I have running on my old HDD). Then I installed the OS on the SSD through the USB port using a Sata-USB, and it booted like a charm.

Next I switched the SSD for my internal HDD and tried to boot, that's when I came into trouble. A message saying "unapproved caller. Security Agent may only be invoked by Apple software". Then I connected the old HDD trough the data cable and booted, no problem.

Why is my SSD only working when attached to the USB and not when it is internal? I read somewhere to check the firmware, but I couldn't quite figure it out. I currently have SMC-version: 1.68f99 and Start-ROM-versjon: MBP81.0047.B2C.

Thank you very much for help.

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Go to Sierra. This failing, replace the hard drive I/R cable with one from the 2012 model.


\Yes, all the complaints on this issue are with El Capitan. Buy the cable without the bracket to save a little bit. Only get new cable! In my opinion this is a very easy replacement but I've done it over a hundred times. The main difficulty is is inserting and locking the IR cable into the bracket and takes a steady hand, See step #12 of this guide:MacBook Pro 15" Unibody Mid 2012 Hard Drive/IR Sensor Cable Replacement

Note on this guide that there is a channel that the cable runs through (I do not believe this is, indeed a 2012 machine but a 2010. Only one machine in the 2009-2012 had this channel. On some machines the bracket that hold the hard drive in place will hit the new cable and/or the screw holes that hold the cable to the frame are to narrow. In these cases I use one one screw and break the bracket so that it does not hit the cable and put the left hand portion of the broken bracket in to hold the hard drive in place. Once I have it all put together, I use Kaptan tape to hold the cable in place and keep it down on the optical drive. I then put pads or Red Tape on either side of the cable to prevent the bottom case from touching the cable and damaging it again.

MacBook Pro 15" Unibody (Mid 2012) Hard Drive Cable

MacBook Pro 15" Unibody (Mid 2012) Hard Drive Cable Image


MacBook Pro 15" Unibody (Mid 2012) Hard Drive Cable


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Just to clarify. You mean install Sierra instead of El Capitan or Yosemite? and if this fails, buy and replace the whole sata cable or just the I/R connection? Regarding the data cable: I've looked into that and it seems fairly difficult, with regards to the adhesive and the small I/R connection. This is my first repair/upgrade job.


See update to answer.


Thanks for all the help so far mayer. I just want to be sure, if I buy whole bracket I do not need to complete step 12? Then I will proceed as follows:

1. try and install sierra on the SSD while internal, from a bootable partition on my old HDD. If it works and boots perfect.

2. install Sierra on the SSD while it is external, and boot from there. If it works, move it inside the mac and try and boot from there. If it works then perfect.

3. Replace my hard drive cable with the one you suggested above and then insert ssd (which probably will have sierra from step 2) and boot.


Sounds like a good plan ;-)


Thank you for the help mayer. I do in fact need to change the internal cable. I got the drive running internally using Sierra, but it didn't answer to all my commands (just Safari worked properly). Hopefully it will run smoothly with the replacement cable. Have a good day and keep helping people.


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Martin will be eternally grateful.
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