Mac Mini stuck on mute

[macapple263]

A few days ago I noticed that my mac mini was on mute so I tried the shortcut keys on my key board and they don't do anything so I go to system
preferences > sound and it shows the mute check box checked and grayed out and above in the drop-down box where you are suppose to select what the audio sources is, is empty it used to say internal speakers, line in, and line out. (It is a mac mini 2006 if that will help figure out the problem)

[pokeyjoe]

From one of the links in this forum:

Resetting the PRAM
From Mac Guides

This is a common Mac troubleshooting procedure, and fixes a multitude of software and hardware problems.

'PRAM' stands for 'Parameter RAM', and contains the following stored information:

* Display and video settings such as refresh rate, screen resolution, number of colors
* Time zone setting
* Startup volume choice
* Speaker volume
* Recent kernel panic information, if any
* DVD region setting

Note: Mac OS X stores your preselected DVD region choice in PRAM for easy access. Resetting PRAM does not change the DVD region on the optical drive.

You will not lose any data stored on your Mac's drives, and system and application preferences besides the above will remain intact.
[edit]
How to Reset your PRAM

1. Reboot your Mac
2. Hold down Command (Apple) - Option (Alt) - P - R
3. When you have heard the chime for the second time, release the keys and the Mac will boot as normal
4. Once your operating system has loaded, you may need to verify your time zone, startup volume, and volume settings using System Preferences.

[CJS7070]

I had this problem, all my input/output sources were missing, turned out to be a disconnected ribbon cable inside the machine. I'm not sure how this could happen if you didn't open it up or do anything, but reseating this cable worked for me.

[MacHamster68]

reseteing pram should bring it back , if its software related ,
if its hardware
its will be be a loose wire

[lostime]

my MBP does this sometimes when I am booting back and forth to windows. The optical/analog headphone input jack can get stuck on the opposite of what you want. Easy fix for me is to unplug and plug in the headphone cable and it fixes itself.

[Farrs44]

Hi, this post may be too late for the OP but may assist anyone out there searching this problem on Google. I have had this problem also on my Intel 2.0GHz Core 2 Duo Mac Mini. I have tried some of the software solutions such as zapping PRAM, etc. But in my experience the fix that works is to open your Mac Mini and unseat and then reseat the orange Foxconn ribbon audio cable where it connects from the Mini's audio board to what I assume is the main circuit board. Then when you reassemble and turn on your Mac, audio will be back.

My theory is that unplugging and re-plugging USB and audio cables on the back of the Mini near the audio board eventually loosens that ribbon cable and causes the audio to stop working and the volume control to become grayed out. My latest attempt at a permanent solution is to have USB and analog 2.5mm stereo audio 'extender' cables plugged in on the back of my Mini, which loop forwards over the top of the Mini where they are all taped down securely. This allows me to plug and unplug cables without ever disturbing the actual USB and audio ports on the back of the Mini around the audio port. It is a somewhat ugly solution but seems to be working so far.