sound won't unmute on lion 10.7.4

[serifstelar]

hi everyone,

this morning my computer started with the mute box checked in system preferences/sounds and it's grayed so i can't uncheck it. Songs won't start on iTunes, i tried both with the internal speakers and headphones. i hadn't do any system changes recently, i updated to 10.7.4 when it just showed up. my iMac it's a mid 2010. please help.

thank you!

 

[flatfoot]

Sounds like your Mac can't access the kext file for your audio chipset.

If a simple reboot doesn't fix it, repair permissions. If that doesn't fix it either, reapply the 10.7.4 update, preferably from the combo update, which can be downloaded from Apple's website (http://support.apple.com/downloads/#10.7.4%20combo).

 

[ellaimac]

Sounds like your Mac can't access the kext file for your audio chipset.

If a simple reboot doesn't fix it, repair permissions. If that doesn't fix it either, reapply the 10.7.4 update, preferably from the combo update, which can be downloaded from Apple's website (http://support.apple.com/downloads/#10.7.4%20combo).

Off-topic: How in the world do you put i7 on a Power Mac!?!?

 

[flatfoot]

Off-topic: How in the world do you put i7 on a Power Mac!?!?

Follow the link.

 

[Adamph]

Just fixed the very same problem.
so far Booted up about 6 times and sound has resumed functionality each time.
Going back to 10.7.3 didn't really resolve the situation, sound would still be sometimes greyed out and and the machine had slowed to a crawl so I rung apple and they recommended resetting the SMC and PRAM. Worked for me.

do SMC first

http://support.apple.com/kb/HT3964
http://support.apple.com/kb/HT1379?viewlocale=en_US&locale=en_US

 

[serifstelar]

Just fixed the very same problem.
so far Booted up about 6 times and sound has resumed functionality each time.
Going back to 10.7.3 didn't really resolve the situation, sound would still be sometimes greyed out and and the machine had slowed to a crawl so I rung apple and they recommended resetting the SMC and PRAM. Worked for me.

do SMC first

http://support.apple.com/kb/HT3964
http://support.apple.com/kb/HT1379?viewlocale=en_US&locale=en_US

later edit: the problem came back after resetting the SMC and PRAM, so if anyone has another solution, please help.

 

[JimOHara]

sound won't unmute on lion 10.7.4

Same thing happened on my 2010 MacBook upgraded to Mountain Lion. Read on another board that docking may resolve. I don't have a full-blown dock, but do have an external Apple keyboard. I shut down last night with the keyboard plugged in, sound muted. Started this a.m. without external keyboard; could not unmute. Plugged keyboard in and rebooted. Was able to unmute.