Bypassing the EFI Firmware Password on a Mac
I found myself in a particularly nasty place yesterday. I had followed advice given to me by an Apple engineer and either what they told me to enter in terminal was wrong, OR, I mistyped. Either way the result was a iMac that would not boot and gave a kernel panic at every grey boot screen. I tried resetting the PRAM/NVRAM via command-option-P-R, I tried booting from single user mode, booting to safe mode and booting from the DVD to bypass the HDD. None of these worked and all resulted in the kernel panic.
So i call Apple care and the guy there was fantastic and he determines a fried logic board and happily gives me a case number to have it repaired under warranty. Now I have been a Mac user for long enough to know that you don’t (Most of the time) go from working fine to rebooting and having a fried logic board. So I racked my brain and spent hours on Google and I am happy to say I fixed it, and I will share with you what the issue was and how I fixed it in the hope it may help many others in the future.
Now for reasons I won’t delve into I have an EFI Firmware password set on my Mac. I presume if your reading this article your the same. The EFI firmware password essentially stops you doing any of the important key combinations at boot, resetting PRAM/NVRAM, single user mode the whole shebang. Now this is useful in many many circumstances except when your screwed like I was. Essentially when I thought I was resetting my PRAM and NVRAM I was doing absolutely nothing. If your as screwed as I was and cannot get to a DVD to boot OR you have forgotten your password there is only one way around it.
- Add or remove a stick of ram. Obviously if you have one stick in, add one and if you have two in remove one.
- Power on the mac and immediately press and hold command-option-P-R.
- The system will restart with the ‘bong noise’, allow it to do this 3 times. On the third ‘bong’ you can let go of the keys.
- The machine will now boot with a cleared password and reset PRAM/NVRAM.
- You can shut down the machine and replace the original ram configuration.
I hope this helps anyone that was in as much hot water as me! Good luck 
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27 year old oil worker based in Aberdeen, Scotland.
April 13th, 2008 at 8:51 pm
And if you happen to have a certain mac laptop with soldered-on ram chips?
April 13th, 2008 at 10:35 pm
Hey Paul, I think at that point you cry
May 20th, 2008 at 2:03 pm
Hi admin.
Same problem on a used 20″ iMac a friend purchased. Found many tips online – tried them all including yours – no luck! According to an Intel engineer there has to be a jumper somewhere to reset EFI. Are you sure you weren’t dealing with open firmware, and not EFI?
May 22nd, 2008 at 12:58 pm
Pablo, I’m certain, Open Firmware is only on the PPC Macs, EFI only on the Intel ones.
December 26th, 2008 at 11:27 am
Worked a charm – THANK YOU VERY MUCH
Saved my bacon.
April 27th, 2009 at 8:38 am
Ive tried it on a imac 17 intel early 2006. I had to change keyboard to a non -alutype, and i reset SMu (remove all cables for min 15min) before changing RAM. it worked .
thank you very much. sending you lots of good vibes from oslo norway.
inge jclauysen
May 13th, 2009 at 7:51 am
Your solution worked. Thank you very much! You saved me 3 weeks work and alot of hassle. From now on I will backup more regularly. My screen went black after waking it from sleep. I have made no recent upgrades. I haven’t been able to fix that, so I will have to let an Apple service provider have a look. However, I had accidently turned on Firmware password when upgrading the Firmware in April 2008, so I couldn’t try the standard rescue operations, like safe-boot or using my computer as external HD. My system is a MacBook Pro 2.1 (Santa Rosa, bought mid july 2007) with OS 10.4.11. Your solution let me remove the Firmware password and clone the HD using another Mac. Now I can boot the system from another Mac (MacBook OS 10.5.6) while waiting for the computer to be fixed.
July 7th, 2009 at 4:14 am
Thank you SO MUCH! Saved my life!!! I could cry right now.
August 18th, 2009 at 3:09 pm
You saved my life!!!
Thxs
February 26th, 2010 at 12:38 am
[...] up firmware password protection in Mac OS X. If that is what you are seeing try these directions. Bypassing the EFI Firmware Password on a Mac | David J Moore __________________ Sylvester Roque Contributing Editor About This Particular Macintosh [...]
March 17th, 2010 at 6:07 pm
Still seems to work thank you for the post
May 19th, 2010 at 8:17 am
that worked for me as well by taking one of the ram out which i had a 2gb ram and reseted iit bi holding apple and command and p and r holding on to it, but i did this 4 times stimultanueously, then switched it off, put back in the ram i took out and installed mac os x on my imac a1224 and it was fine…
May 31st, 2010 at 7:30 pm
Dear sir,
I was intrigued by your solution to my problem and wish to contribute to the costs of a statue for you.
June 7th, 2010 at 5:27 am
this works exactly as instructed.. thanks
June 13th, 2010 at 8:45 pm
Hello, thanks for your advise. I have a new MacBook unibody white, and I tried your solution and still doesn’t work. I cannot boot from a cd, etc and no way to disable efi or firmware protection.
Any advise? Thanks very much.
June 13th, 2010 at 8:46 pm
Please, i will appreciate your help. Hello, thanks for your advise. I have a new MacBook unibody white, and I tried your solution and still doesn’t work. I cannot boot from a cd, etc and no way to disable efi or firmware protection.
Any advise? Thanks very much.