Mirroring display on external monitor while reformating

Discussion in 'MacBook Pro' started by effahmed, Feb 9, 2017.

  1. effahmed macrumors newbie

    Feb 9, 2017
    I am having an awkward problem with my MBPro which i'll try to explain as succinctly as I can:

    • The screen of my MBPro (Early 2011) cracked, leaving me unable to see whatever was happening on the screen (photo below). I plugged in a Toshiba external monitor via HDMI cable and mirrored the display. This way I could see the screen of my MBPro.
    • When my new MBPro arrived, I had the clever idea (sarcasm) to reformat the old MBPro to get a 'clean slate'. I created a backup of Sierra on an external HD and reformatted the machine using CMD+R command (external monitor setup was working fine till this point)
    • Once the reformat was done, I booted the machine pressing Option key to reinstall Sierra but I was not able to get a display on the external monitor. I've tried plugging/unplugging the HDMI cable and CMD+F1 but without any success.

    I would like to be able to get the display back on the external monitor so I can finish the reinstall. Any advice on how to do this would be appreciated!


  2. rutrack macrumors regular

    Jan 5, 2017
    Maybe you could connect external keyboard and mouse and run your laptop in clamshell mode ?
  3. ZapNZs macrumors 68020


    Jan 23, 2017
    IIRC, with my 2011 MBP, when using an external it would NOT show an image on the external until after the initial EFI sequence...

    But I have an idea if all else fails... (I have my moments here and there)

    You can remove the HDD or SSD from the 2011, throw it into a SATA-USB-3 enclosure, plug it into your new Mac, format the hard drive, and then install OS X onto the external (then pop it back into the 2011, boot it with the monitor connected, and then continue setting it up.) It's a little more work but shouldn't be too bad. :)

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