Currently Being ModeratedApr 30, 2011 5:41 AM (in response to mohanfromajax)
Are you talking about Input via the built-in microphone, or Output through the built-in speakers?
If it's the speakers that are nonfunctional, is there a red light inside your headphone port? If so, see this recent thread:MacBook Pro, Mac OS X (10.6.7), '08 15" 2.4GHz; 27"ACD; Pentax K-7
Currently Being ModeratedApr 30, 2011 6:48 AM (in response to eww)
Output through built in speakers. There is no read light in the head phone jack.
when i go to system preferences, sound and go to output tab I should see built-in speakers. But there list is empty and there is no device for sound output
Currently Being ModeratedMar 21, 2012 2:14 PM (in response to mohanfromajax)
I just had this happen, where my "Sound" preferences had digital output listed, but no internal speakers. So my speakers would not work. Tried turning the macbook pro off and starting it back up with no luck. When I plugged in a set of headphones and played a song in iTunes, the sound came through the headphones. When I unplugged the headphones the internal speakers started working again. Yay!
Currently Being ModeratedMar 21, 2012 2:57 PM (in response to DBoy)
That's why eww asked if there was a red light in the headphone jack. If it's there, the changeover switch has stuck. It's only a piffling little leaf contact and this is not an unuasual problem.
Currently Being ModeratedJun 27, 2012 8:03 AM (in response to mohanfromajax)
My solution for "No Sound Output to MacBook Speakers" - Re-route Sound Input / Output
I have had this problem on my MacBook Pro, and tried EVERYTHING Apple & Forums suggested - SMC reset, PRAM reset. Apple advised me to send it in for servicing. Since it isn't covered by warranty, I didn't want to do that.
If you do not want to pay Apple to fix your MacBook optical sound jack hardware, you can overcome the problem with this procedure I came up with myself, which overcomes the hardware failure caused by the headphone jack optical sensor thinking something is plugged in there when there isn't.
Ironically, this solution requires a jack be inserted into the headphone jack. Annoying, but workable and free.
Step 1. Plug headphones in (don’t worry, you won’t use them)
Step 2. Change System Preferences -> Sound -> Change Internal Speakers to an Input!
Step 3. Done!
Obviously when you do want to use the headphones, you must revert this setting.
Hope this helps!
DougMacBook Pro, Mac OS X (10.7.2), Intel Quad Core
Currently Being ModeratedSep 26, 2012 2:31 PM (in response to noondaywitch)
I am having the same problem. When I plug in headphones the sound works, but when I take them out it does not work and there is a red light. What can I do to fix this?
Currently Being ModeratedSep 26, 2012 2:59 PM (in response to Meghan1994)
If you can see a red light, the port is still live, cutting off the internal speakers.
The cause is a little leaf switch that is pushed over by the jack when you insert it. Sometimes these stick.
Try inserting and removing a jack a few (dozen) times.
If that doesn't free it you may attempt to tease it with a slim non-conducting tool (like a toothpick). Ensure the Mac is not only shut down, but unplugged if you try this.
And be careful; the leaf is fragile and it's an expensive bit to get to and replace, in fact on some models it's directly on the logic board.