MacBook Pro mid-2012 have to wait 30min between reboots

Question

My MacBook Pro mid-2012 has been acting up lately. A year ago I replaced the original hard drive with a Samsung SSD 850 EVO 1TB, and everything was fine. Then the SSD became corrupted and was exchanged under warranty. Since installing the second SSD I've installed a fresh copy of the latest macOS Sierra on a single 1TB partition and have been having issues ever since.

The symptoms are:

• Random fails: When I wake it up from sleep or open the lid I find it with the "grey screen with crossed circle" (Similar to this: https://qph.ec.quoracdn.net/main-qimg-b29f58e707cef6f20a882248f4ee558c).
• Fails to find a bootable volume when rebooted (or even after a shutdown and reboot) within a ~20-ish minute timeframe (boots to the folder icon with a question mark, similar to this: https://i.sstatic.net/V5agg.jpg). I have to wait and try to boot it again later. Then it boots as if nothing happened.

What I have done:

• Reset the NVRAM. Result: no significant change in behaviour
• Reset the SMC. Result: no change in behaviour
• Did the Disk Utility trick where I modified the size of my partition, then set it back to a single 1TB partition again, in order to have Disk Utility rewrite the partition map (or something). Result: now it doesn't constantly fails when I close and reopen the lid. Although it may have been the result of the next point.
• Changed the energy settings to default (I have a script I run when I setup a new computer, and it includes some non default power management settings). Result: see previous point.

Questions:

• Does this seem like a hardware failure or a software failure?
• What can I do to be sure either way?
• Any suggestions on how I can reliably fix this?

I have several full backups of my data, so I can try virtually anything. I'm determined to find out how to fix this. Perhaps installing a stock version of macOS Sierra and not changing anything at all, and using it like this for a few days could help me figure things out in more detail?

Answer 1

Some Mid-2012 MBPs had an issue with the Hard Drive Flex cable that could cause similar issues (at least as far as the Booting to a Folder with a Question Mark), so I might be worth calling Apple or heading to an Apple Store to have them have a look.

If it is one of those ones, you may get a repair for free for it. I gotta stress though, it isn't ALL mid-2012s, just some of them. Mine wasn't one of them (I had permanent "No Hard Drive Detected" but the tech I saw initially thought it was, hence me knowing anything at all about it).

If it is the cable that is faulty, it didn't cost a lot out of warranty anyway, although if you are getting the odd Prohibitory symbol, then you may want to reformat the drive and reinstall OS X anyway to get rid of any filesystem problems that would still be there beyond hardware

Answer 2

Two things you don't seem to have tried as troubleshooting steps are to try booting your MBP into Safe Mode and also running Hardware Diagnostics.

Boot into Safe Mode

Follow these steps boot your MBP into Safe Mode:

1. Fully shut down your MBP
2. Restart your MBP
3. Immediately press the Shift key and keep it down
4. Let go of the Shift key when you see the login window (NOTE: If you have FileVault enabled you may need to log in twice).
5. Take a note of what happens (i.e. could you boot your Mac okay, are you still experiencing the same issues, etc)
6. Exit Safe Mode and restart your MBP as normal
7. Again, take a note of what happens (i.e. could you boot your Mac okay, are you still experiencing the same issues, etc)

If the above seems to make no difference, then see below to run Apple Diagnostics.

Run Apple Diagnostics

Follow the steps below to run Apple Diagnostics:

1. Fully shut down your MBP
2. Restart your MBP
3. Immediately press the D key and keep it down until you see the Diagnostics screen appear
4. Wait for Diagnostics to finish (this typically only takes a few minutes)
5. Once complete, one of two things will appear on the screen:
   • a No issues found message
   • a brief description of any errors found plus further instructions
6. If the diagnostics test does find errors, take a note of what they are

Note: If pressing and holding the D key at Step 3 doesn't work, start again at Step 1 and, at Step 3 press and hold both the OptionD keys instead. This will try and run diagnostics from the internet instead, so you will need to allow more time for it to complete.

Regardless, take a note of what happens and let me know how you went.