Disable startup sound on iMac 2007

[Member punranger]

Hi,

I just got a 24″ iMac from 2007 for 50 bucks from a guy in the neighborhood – he was even as kind to drive it to my doorstep. The machine is pretty much in mint condition, and antiX 21 works great. One small problem though: The iMac insists on playing the typical Apple startup sound.

I have searched for fixes, but all of them seem to hinge on booting into the Mac OS recovery mode. Problem is, I wiped everything when I installed hard disk, and the only thing available is the EFI boot option which boots antiX. I tried several key combinations, but to no avail.

Alexander Todorov suggests the following:

# efivar -l | grep SystemAudioVolume
 7c436110-ab2a-4bbb-a880-fe41995c9f82-SystemAudioVolume
 7c436110-ab2a-4bbb-a880-fe41995c9f82-SystemAudioVolumeDB

# efivar -n 7c436110-ab2a-4bbb-a880-fe41995c9f82-SystemAudioVolume -p
GUID: 7c436110-ab2a-4bbb-a880-fe41995c9f82
Name: "SystemAudioVolume"
Attributes:
    Non-Volatile
    Boot Service Access
    Runtime Service Access
Value:
00000000  00                                                |.               |

# efivar -n 7c436110-ab2a-4bbb-a880-fe41995c9f82-SystemAudioVolumeDB -p
GUID: 7c436110-ab2a-4bbb-a880-fe41995c9f82
Name: "SystemAudioVolumeDB"
Attributes:
    Non-Volatile
    Boot Service Access
    Runtime Service Access
Value:
00000000  00 
#

Found at http://atodorov.org/blog/2015/04/27/disabling-macbook-startup-sound-in-linux/

However, I could not execute the commands on my vanilla setup. I don’t have the readout on hand, but will post it if that is helpful.

Any help appreciated.

antiX linux: The best way to revive an old computer - https://www.youtube.com/watch?v=JCTaUAP6sSg

[Member Lubo]

Helpful

Up

0

::

I’ve worked with a lot of Macs over the years, so I have two suggestions to try.
It appears this is the model of iMac you have:
https://everymac.com/systems/apple/imac/specs/imac-core-2-duo-2.4-24-inch-aluminum-specs.html#macspecs2

1) Get a Mac OS .dmg such as those used to install it. Put on a USB drive and boot from that. Proceed with commands like nvram issued from Mac OS terminal. Shutdown. Remove USB drive. Should be a one time fix if settings are saved properly. And you won’t have to touch your hard drive. Getting the install disc image and copying it to USB is the hard part, if you get that done, the rest should be easy.
This is also discussed at length on forums like this one:
https://unix.stackexchange.com/questions/536436/linux-modify-an-efi-var-with-efivar
Some of the solutions are “try at your own risk”, but some posters say they were done entirely in Linux.
EFI, like Open Firmware before it, is a bit of a black box. Lots of Apple (or in this case Intel) mumbo-jumbo.

2) A work around rather than a solution, but may be ok, depending on how much you use sound.
That iMac is supposed to have an audio out jack. Having something, even a audio jack with no wires or a broken set of earphones, mutes the sound. Not ideal, but it should prevent all sound.

• This reply was modified 9 months, 1 week ago by Lubo.

Mr. Lubo Diakov
email: zr90004@gmail.com

[Author]

Posts