After a harrowing couple of days, I found this site and am hoping someone can help.

I have a 2011 MacBook Pro which has recently started having problems booting. During a game session (SIMMS), it suddenly shutdown and refused to reboot, and since then I've been unable to use it at all. The MBP has a new install of El Capitan on it but it's been working fine for the last couple of weeks since the install.

I tried Safemode, Recovery mode etc, but it wouldn't boot into any of these either. Eventually I set it to Target mode, and reloaded El Capitan from another "Companion" MacBook Pro. This process went without a hitch.

After loading it, I booted from the "companion" MacBook to make sure the OS was working OK, and it was!

I restarted the "Companion" MBP and ejected the faulty MBP, and tried to restart it normally. No go, still wouldn't boot even with the new OS.

I've tried a number of things to get it to boot, following this fresh install, but all that happening is that it'll get to the Apple Logo, try to boot, shutdown and then go around in circles.

Eventually it'll stop on the gray screen and the fans will startup and keep running.

I'm at the end of my knowledge, so any advice would be welcome!


  • See my answer to this for some standard first steps - apple.stackexchange.com/questions/219795/…
    – Tetsujin
    Jan 3, 2016 at 10:08
  • Yup tried all the usual NVRAM, SMC resetting and trying to boot in safe mode (etc), still can't get past the grey screen looping, and the AHT returns no faults found. I'll be removing the HDD today, and will try to connect externally - happy to try almost anything to diagnose if it's the logic board or something else. One other thing I noticed yesterday - when it tries to boot - "SOMETIMES" (not every time), I get a blue-ish horizontal line about 10mm wide filled with pixelation, across the screen for about 2 seconds.
    – Steve G
    Jan 3, 2016 at 19:53
  • Also won't boot from either a USB or DVD to re-load the OS, can't get into the Disk Utility screen to erase from there, so had to set to target mode and work from the companion machine. Even with the HDD erased, it wouldn't boot from USB or DVD - I've never encountered that previously.
    – Steve G
    Jan 3, 2016 at 19:55

1 Answer 1


Have you had a luck with it yet?

Sound like it may be similar to mine. Logic board for Mac Book Pro's sold between late 2011, whole 2012 and start 2013 are under Apple's Extended Warranty Program. Your symptoms are the same as what I had before mine completely died. Going in tomorrow to have my logic board replaced for free. Thanks Apple.

Please see the link below.


Hope this helps.

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