iMac won't detect built-in speakers

[yapi]

Last night my iMac experienced [yet another] kernel panic, and now suddenly it won't detect my built-in speakers. Even when I plug in external speakers it still won't make a sound. I checked in system preferences and sure enough, under sound>output device it says that there is no device detected.

Could anyone help me with this? I already tried repairing permissions, repairing my disk, doing the hardware check, and I just reformatted a couple days ago

[elbert]

Have you tried creating a new user? Try that and see if the problem is not isolated to your user profile.

[yapi]

Yup, I tried it. Still no good. Would it be any different if I turned fast-switching off? Any ideas on why this is happening?

[Arel]

When my iMac (CRT) encountered the same prob, resetting the PRAM got my speakers working again since speaker volume's stored in it.

Resetting PRAM and NVRAM

1. Shut down the computer.
2. Locate the following keys on the keyboard: Command, Option, P, and R. You will need to hold these keys down simultaneously in step 4.
3. Turn on the computer.
4. Press and hold the Command-Option-P-R keys. You must press this key combination before the gray screen appears.
5. Hold the keys down until the computer restarts and you hear the startup sound for the second time.
6. Release the keys.

Hope this works for you, Yapi. Good luck!

[Edited on 8-9-2004 by Arel]

[yapi]

I just tried resetting the PRAM and it's still the same. Fortunately though, I do still have a startup chime which means that my speakers aren't broken or anything.

If I remember correctly, there's another thing you can zap, but I can't remember what it is or how to do it, but it's similar to zapping the PRAM. Can anyone tell what it is from my vague description? :blush:

[marvinp]

Reset the NVRAM. Restart and hold down Command-Option-O-F until you get the > prompt.

Type:
reset-nvram (press return)
set-defaults (press return)
reset-all (press return)