Step 5: Reset the NVRAM, because, why not?
In the PowerPC days, we talked about resetting the PRAM. On modern Macs, the real term is resetting the NVRAM. The name refers to special memory sections on your Mac that store data that persists even when the Mac is shut off, like volume settings, screen resolution, and similar options.
Resetting that data isnt harmful, and quite frankly its also rarely genuinely useful. But man, at this point, it cant hurt.
You might need to grow an extra finger or two for this one, or have a friend help you out. Hold down all of these keys: Command, Option, P, and R, and turn on the Mac. Keeping holding the keys down until you hear the Mac restart again. Apple says to let it restart just the one time; I usually listen for a second reboot, and then release the keys.
In some cases, after performing this step, your Mac will restart normally. In other cases, if your luck is as bad as Julians was, you might instead see a progress bar on startup. If the progress bar fills up and then the Mac starts up, youre likely good to go. In JVs case, however, his Mac actually shut down at around the halfway point in the progress bar.
It was time for Step 6. Oh, Step 6.
Step 6: Make a Genius Bar appointment
Julian and I went to my local Apple Store with his Mac. We made one rookie mistake, which Ill get to in a moment.
We explained the problem in detail, and went over all the steps wed already tried. That was good. The Genius behind the bar agreed that it was probably a hard drive issue, and wanted to check to see whether the drive simply needed reformatting, or actually exhibited bad sectors indicating it needed to be replaced.
While we were there, Julian realized he hadnt backed up certain important files that had been on his Macs desktop. The Genius we worked with (Adam) could get Julians Mac to boot in Recovery mode, as we had, and we were able to copy the other files from it. But our mistake was that wed left Julians external drives back home. So JV had to plunk down extra cash to buy a thumb drive at the Apple Store, onto which we then copied those other files.
After consulting with a second Genius, Adam rendered his verdict: Because the drive wasnt reporting any bad sectors, reformatting it and starting over would likely cure what ailed Julians Mac.
We returned to my house, fired up OS X Recovery again, and launched Disk Utility once more, choosing to erase Julians Mac completely. Then we reinstalled Mountain Lion again.
The Mac started up beautifully. Julian returned home to New York.
Several hours later, as he restored his data from his backups, Julians Mac started behaving badly again. Eventually it crashed hard, and again refused to start up.
Step 7: Go back to the Genius Bar again
Sometimes, even the best experts get it wrong. The new diagnosis for Julians Mac was that it was, in fact, a logic board failure, and not a fault with his drive at all. Apple took custody of JVs MacBook Pro, and in a few days (and for nearly $300), the store will swap out the laptops logic board.
So did we waste all our time with the earlier steps? Hardly.
First, we managed to get Julians Mac usable enough to back up crucial data. That was probably the most important step we took.
Second, all those steps ruled out numerous other issues; it was because of the freshly-wiped hard drive that the new Genius was able to conclude a logic board failure was to blame for JVs Macs problems.
So while our steps didnt work this time around, thats only in the sense of actually solving the problem at hand. They did help to ensure the safety of Julians data, and at least led us to the eventual answer. (Possibly, anyway. It could be that the logic board diagnosis is off-base, too.)
But having these steps and awkward key combinations committed to memory, or saved to an iPad, or stuck on your refrigeratorthat can make coping with your next Mac disaster considerably less stressful. Presuming your backups are current, anyway.
This story, "When good Macs go bad: steps to take when your Mac won't start up" was originally published by Macworld.