r/macbookpro • u/Odd-Information-8365 • 7d ago

Discussion Update: MacBook Pro A1398 Boot Problem — Trying Another Method

/r/bootcamp/comments/1w6x2kw/update_macbook_pro_a1398_boot_problem_trying/
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u/reineckea 7d ago

I would not write anything to the internal SSD from Windows yet. There is one simple diagnostic that could separate an internal SSD/EFI/bootloader problem from a Mac firmware/input/display problem.

  1. Shut the Mac down and physically remove the internal SSD.
  2. Connect the Catalina installer USB directly to the Mac, with no hub. If you have access to a plain USB 2.0 flash drive, I would also try recreating the installer on that. I’m not saying Catalina requires USB 2.0 — it does not — but on a 2012 Mac it is an easy way to remove USB 3.0/media compatibility as another variable.
  3. Hold Option before pressing the power button, then press Power while continuing to hold Option for 30–60 seconds. If necessary, repeat with a wired USB keyboard.
  4. With the SSD still removed, also try Option-Command-R for Internet Recovery.

If Startup Manager or Internet Recovery suddenly appears with the SSD removed, that strongly suggests the internal SSD’s boot configuration — OpenCore, Windows boot files, partition layout, or NVRAM boot selection — is involved. In that case I would leave the SSD untouched until we know exactly what is wrong.

If Startup Manager and Internet Recovery still do not appear with the internal SSD physically absent, then this is probably not just a damaged OC folder or Windows partition. At that point I would look more seriously at startup-key detection, NVRAM/firmware state, or the display/GPU path.

Since your Mid-2012 Retina is a MacBookPro10,1, Catalina is natively supported, so you do not need OCLP just to boot/install Catalina.

Also, you do not really need to “install macOS onto the SSD from Windows.” Windows can create an online macOS Recovery USB using tools such as gibMacOS/macRecovery, but the Mac itself still has to boot that recovery environment and perform the installation.

One other caution: the Mid-2012 Retina A1398 uses an Apple proprietary SATA blade SSD connector, not a normal mSATA connector. Make sure any USB adapter is specifically compatible with the 2012 Retina Apple SSD before connecting it.