cure-all for OSX & iOS


When your Mac starts acting up – and they actually do, don’t believe the fanbois bullshit about perfect computing forever, there aint no such thing – you’ll probably run through some basic troubleshooting procedures, such as restarting, verifying permissions in Disk Utility, and using Safe Boot. I recommend that a well-rounded repair skillset should also include what’s known as zapping the NVRAM (formerly PRAM) and resetting the SMC. Personally, I use this procedure before Safe Boot & verifying permissions – it’s a general cure all for random Mac maladies.

History Lesson
Back in the day, the standard list of quick fixes for random Mac ailments (see, they’ve always existed!) included “zap the PRAM.” The P in PRAM stood for parameter (the RAM was just RAM—random access memory), and it referred to a small amount of special, battery-backed memory in every Mac that stored information the computer needed before it loaded the operating system. If the values in this memory got messed up somehow, you’d have start up issues, or maybe a number of strange behaviors when booted. So you could press a key sequence at startup to reset (or “zap” – which is far more emotive than “reset”, you reset a PC while you zap a Mac.) the PRAM, returning it to fresh factory values.

Back To The Future
Intel-powered Macs no longer use PRAM; they instead use something called NVRAM (NV for non-volatile). NVRAM, for all intents and purposes, serves the same role as PRAM (only fewer chunks of information are held). NVRAM is more reliable than PRAM so corruption is fairly uncommon, but if your Mac isn’t doing things as smartly as it once did or has an odd problem with video or sound particularly, then give it a zap. You won’t lose anything and it’s quick & easy to do. (Apart from the requirement for 6 fingers on each hand.)

How To
Reset NVRAM by shutting down your Mac, then press the power button. As soon as you hear the startup chime, hold down Command-Option-P-R together – that’s 4 keys held down. Keep holding down those keys until you hear a second startup chime. Then let go and allow your Mac to continue starting normally. Then check the Startup Disk, Display, and Date & Time panes of System Preferences to make sure they’re set the way you want them.

iMac & Mac Pro only
If you’ve got a desktop Mac & after this procedure see nothing but a gray screen that doesn’t change for several minutes—no Apple logo, no progress bar, no second startup chime—don’t panic.  Well, alright then, panic but only for a short time, 2-3 mins then read the rest of this post.

The most likely cause is that your Mac isn’t registering the key presses due to wonkiness with a USB device. Disconnect all USB devices (except your keyboard, if it’s a wired keyboard, else why hold the keys down? Duuuh), then repeat the process. If that doesn’t work and you’re using a wireless Bluetooth keyboard, try plugging in a USB keyboard instead. Once you’ve reset the NVRAM successfully with the wired keyboard, you can go back to your Bluetooth keyboard.

Reset the SMC
Now there is another component that holds system settings that sometimes needs clearing, of course there is. I mean why would you make it simple? Why should users be able to fix Apple fuck-ups too quick & easily? Anyway, I digress. (Megabyte is somewhat prone to digression)

SMC is the System Management Controller, which deals with power management, temperature monitoring and fan control, status lights, keyboard backlights, and a few other bits & pieces. If the SMC becomes confused, you’ll experience problems such as excessive fan noise, slow performance, apps that take forever to launch, batteries that don’t charge or charge very slowly, sleep and/or wake malfunctioning and more. Like zapping the NVRAM, resetting the SMC often resolves these PIA problems.

While Apple says to reset the SMC as a solution of last resort, they don’t mention any negative consequences, nor any way to determine for sure if the SMC is glitchy without resetting it and noticing that the problem went away. I’ve reset Mac SMCs lots of times with no side effects, often this has been the solution to a random problem.

Before you can reset your SMC, you must shut down your Mac, as per NVRAM procedure. After that, the procedure varies depending on the type of Mac you have.

Desktop Macs: Disconnect the power cord (either from the Mac or from the AC outlet). Wait 15 seconds and plug it back in. Then wait another 5 seconds and turn the Mac back on.

Mac laptops with non-removable batteries: (Retina MacBook Pro, MacBook Air) Make sure the Mac is plugged in to AC power. On the built-in keyboard, press and hold the Shift, Option, and Control keys on the left side and press the power button. Release all the keys at once, and then turn the Mac on normally.

Mac laptops with removable batteries: Disconnect the AC power cord and remove the battery. Press the power button, hold it for 5 seconds, and then let go. Put the battery back in, reconnect the power cord, and turn the Mac on normally.

Now, while I can’t guarantee a cure via these two methods, both of them can & do solve a variety of odd problems, and are definitely worth a few minutes of your time before calling in your local Mac fixit guy.

iOS Equivalent
This procedure has an iOS equivalent, it’s quick & easy to do & you’ll be surprised how effective it is. I’ve used this method to rejuvenate problems from iPhone with sticky home buttons to an iPad with no picture showing. This method will also cure PIA problems like Apple ID passwords that wont stick or fingerprint IDs that disappear, weak WiFi reception & more. It’s both device and OS version agnostic, an across-the-board solution for various common problems.

You ready? Press & hold both your power button & home button together until the iDevice flashes off & restarts. That’s it, all done. Problem solved? Tell me about it in the Comments section below.

23 thoughts on “cure-all for OSX & iOS

  1. I waited until it showed “wrong password try again” then hit cmd + r for 3 seconds. Five mins later it gave me the password field and I entered my remote passcode and it let me back in. Apple support was clueless helping me out. They told me to go to the Genius Bar with a receipt. Hope this info helps someone

  2. Hi guys..Very interesting information, but I believe the MBA problem smc ,just resetting don’t fix the problem ,I have a MBA with this failure and I have done every kind of fix or solution and the failure continues, seems to be is random.. Sometimes the MBA is in a deep sleep…Don’t wake up..But the next day works very well..Then again next day is dead, deep sleep..I have reset smc , install from clean Sierra , change iCloud account ( this worked fine almost for a month, but then dead again) ,add a guest account , deactivate hibernation..But seems to be nothing works..Is there something I haven’t done yet?? 🙂
    Thanks in advance…!!

    1. There’s a strong wave of public opinion building in regards to 2013+ MBA laptops. No-one can definitively pin the problem down, it manifests in a variety of forms, often so different that you’d swear it was separate issues.

      The one thing they all share – black screen. They don’t go. Still an Apple product but not a laptop any more. Looks like one but doesn’t operate like a laptop should.

      Apple is staring down the barrel of yet another product recall, I’m predicting. Following the 2011/12 15″ MBP faulty graphic processor debacle, this MBA failure is bigger and far more widespread – because they sell far more MBA’s than 15″ MBP’s.

      Don’t bet on this recall though, I don’t make those decisions at Apple.

      I had a client facing this same issue just 3 weeks ago – do you take a punt on a recall, put your MBA in a drawer & buy another laptop until then? Do you buy an MBA again? He had, not contemplating that it might be a widespread problem affecting his original MBA. His assumption was that he’d dropped or knocked his MBA & that had put the ghost in the machine. Nah, not even. It had a bad case of 2013+ MBA-itis.

      $300 spent on a new mainboard fixed it. Then, quick like a bunny, that MBA was sold.

  3. Its a MacBook Air 13 early 2015.It just died and I did Command R and typed in the 4 digit password and continued to boot up and I’m back at the same message Your computer is disabled. Try again in 60 minutes. So im going to wait for 60minutes to see if the password box is back. ill post afterwards

    1. That 60mins thing isn’t real. The same warning on iDevice requires restore from backup or DFU reinstall.

      For your MBA

      1. Power off your MacBook Air
      2. Power on and hold Command-Alt-R buttons
      3. Mac boot with EFI PIN lock (padlock icon with bar)
      4. Enter your 4-digit iCloud PIN or your Apple ID password and press Enter
      5. Internet Recovery process can take about 10-15 min then Mac will boot normally.

      Try that, let us know what happens

      1. Okay it did not work. Just says wrong password after none was typed. I have done option command r and type in the 4 digit password the internet recovery begins and it takes about 10min and reboots and back to the disabled message. I don’t know what else to try I have the 4 digit password. I have also tried powering on and holding option to load a Usb and install a new osx but doesn’t read the usb. So im guessing the efi icloud is blocking it .

        1. You can always go to & do the Remove From Account thing to free your MBA from the evil clutches of Siri & the iCloud.

        2. Pity Brandon, sounds like you getting a similar issue to what we had but not winning…
          strange as i have done my friends macbook air 2015 model the other day and it worked. Not sure what else to do as you seem to be doing everything already.
          best of luck, hope you get it right.

  4. I am also stuck on Disabled 60min and no mater what I do even after entering 4 digit pin and internet recovery can not go past 60min disabled screen. I have not tried the above method of letting the battery die out but will attempt it and post my results. Hope it works.

  5. Im having the same problem as above but in my case there is no way on retrieving the 4 diggit box so i can insert my pincode

    1. Sounds like you’ve gone past the 4-digit opportunity, Jack, you’ve got what looks like a standard password form field on screen huh?

      If so, read the comments above – you might get lucky.

      1. I have tried all the above.. it doesn’t matter what i do on the laptop it always directs me to the icloud screen right
        away telling me to wait 60 minutes. when those 60 minutes pass it tells me that i have inserted
        the code wrong while i didn’t even insert anything.. so again it let me wait 60 minutes and so and so on..

        I just need to find a way to retrieve the 4 diggit icloud padlock and im good to go but i can’t find my
        way in achieving that :((

        1. Apple’s system gives you one chance enter the 4-digit pin. Those amongst us who are so clever as to wipe the hard drive thinking that their IT abilities exceed those of the combined Apple Inc, tend to find, much to their alacrity, that the simple 4-digit opportunity has been replaced by a minimum 6-digit consisting of letters & numbers & special characters too.

          There’s a possible way past, in the discussion above. If not, you may be looking at a parts auction to recoup your losses.

        2. Are u able to attempt to enter the 4 digit code ?
          If so u can crack it with a teensy 3.1 device. I’ve tested and it works.
          I even had the screen not allow me to enter the 4 digit code and said it was iCloud locked .

  6. Macbook AIR iCloud & EFI Lock – Problem Solved !

    1st off thanks to your site for paving the way to getting my macbook air back online.

    I bought a macbook air 2 years back for my wife and when we updated to yosemite last week we ended up with a iCloud find my mac lock and i dead macbook air.

    After reading over 50 posts online, i found out that i needed to get a Teensy 3.1 and run the code cracker.

    needless to say eventually i figured out how to do this and after fiddling around for 2 days, cracked the code:

    The Process:

    1.Macbook was find my mac locked with a 4 digit passcode screed.

    now i messed up here by trying to enter various codes by guessing and eventually ended up with no more passcode screen, only a screen showing ” this computer is disabled, try again in 60 mins” which would count down and then say “wrong passcode”, and nothing would happen. Dont Panic – I DID.

    2.Rebooting with Command + R took me to the next lock screen whereby again i could try guess the code.

    3.Get a Teensy 3.1, and install this sketch of code into it :

    // This code is licensed under Apache 2.0 License
    // Limitation of Liability. In no event and under no legal theory,
    // whether in tort (including negligence), contract, or otherwise,
    // unless required by applicable law (such as deliberate and grossly
    // negligent acts) or agreed to in writing, shall any Contributor be
    // liable to You for damages, including any direct, indirect, special,
    // incidental, or consequential damages of any character arising as a
    // result of this License or out of the use or inability to use the
    // Work (including but not limited to damages for loss of goodwill,
    // work stoppage, computer failure or malfunction, or any and all
    // other commercial damages or losses), even if such Contributor
    // has been advised of the possibility of such damages.
    // This code is indented for people who are not able to contact
    // apple support and I am in no way liable for any damage or
    // problems this code might cause.

    const int ledPin = 13; // choose the pin for the LED
    int counter = 0;
    int fakecounter = counter;
    char pin[]=”xxxx”;

    void setup() {
    pinMode(ledPin, OUTPUT); // declare LED as output

    void loop(){
    keyboard_modifier_keys = 0;
    if (counter 9999){
    for (int blinkies = 0; blinkies < 8; blinkies++) {
    digitalWrite(ledPin, HIGH);
    digitalWrite(ledPin, LOW);
    fakecounter = counter;

    4.My Teensy would insert a 4 digit code every 15 seconds ( thus 4 codes per minute, 240 codes per hour )
    Make a note of the start time and then leave the computer. come back every few hours and (make a note of the time u come back) the reason for this is if u come back in say 3 hours and its still cracking the code then u know that 3 hours is 3 x 240 codes = 720 code attempts and u know that the 1st 720 you can ignore next time . If the code has been found,
    you will know as it would have booted to the next screen showing you Point 1 above ( your laptop is disabled )
    Now you need to work out by a process of elimination to eventually get to the actual 4 digit code.

    you need to modify the above sketch in point 3 to now start from the next set of codes. for example lets say the laptop was on and teensy working for 7 hours and nothing found yet. then work out 7 x 240 codes per hour = 1680. now put teensy into another laptop and modify the start code from 0 to 1680. this is done here :

    int counter = 0; chang the 0 to your new number in this case 1680.

    then start teensy again….. GET IT .

    5.ok so eventually i got the correct code . inserted it and bam was now stuck at the disabled screen again and after reading everywhere was basically totally fucked. no matter what i tried i could not get the 4 digit passcode box back.

    Also all the posts online about resetting the PRAM didn't work as macbook doesn't work .

    6. THE SOLUTION, by some miracle, i thought what if i unplugged the charger and let the macbook air battery run down to dead, then try re power it and lets see.

    so i unplugged the charger, and inserted the correct code after rebooting Command + R.
    as we know i got to the Disabled screen.

    I left the computer for a hour , and when returned the passcode screen was miraculously back.

    HAPPY Fucking DAYS !! inserted the same 4 digit code again and Viola , back in business!

    hope this helps some other out there.

    i am slightly IT index , but the Teensy and coding was completely above my head, and i managed to get it right, so I'm sure you will too .

    1. This is an undocumented cure, as far as I’m aware. Doron & I collaborated (by email, he lives 12000km away) on this over the weekend, my final advice was to flash the EFI (or buy a broken MBAir & transplant) – I couldn’t see another way through.
      Congratulations on your perseverance & your patience – that and thank you for sharing this solution that you’ve found.

      1. Yup, and thanks again to 1024KB for assisting me of the weekend. Once i was able to log back into the mac, i merely created a new iCloud account and the macbook asked to confirm logging out of the old one.

        all working and happy.

        Glad it worked and hope it helps others.

    2. ok I have exactly your same problem and i am stuck on the 60 min loop! so i can’t fully understand your charging approach , so this is what i got:
      1. Let the laptop run out of charge until it’s dead.
      2. Re-charge it again.
      3. Un-plug the charger.
      4. Then Start using command + r and enter the firmware password.
      5. Open the Mac partition (i have windows and it’s working).
      6. wait for the 60 min then the 4 digits will appear? is it correct?

      1. Uhmm, Mohamed, if you have the firmware password then you shouldn’t have the iCloud screen lock problem. A Mac iCloud lock is essentially just that – a firmware password. To be double sure, when you’re in Recovery, click Utilities / Terminal & type this:

        nvram -d fmm-computer-name
        nvram -d fmm-mobileme-token-FMM

        Type it exactly as it reads & you’ll have cleared the remnants of FMM off your Mac.

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