Q: Red light in headphone jack and no sound from internal speakers.

NONE OF THIS WORKED FOR ME

I told myself when I find the cure for the red led light I'll share on this post to help anyone else with the same problem and seem to can't find the solution.

Solution: Spray compressed air spray in the headphone jack

Quick update. The problem is physical. If blowing does not work, get a toothpick and lightly jiggle it in the port (what I had to do after blowing only partially restored sound).

It worked for me! Yey!!!! Thanks sooo much I was beginning to panic

I just put my headphone cable in and twisted it a couple of times and the audio came back to life!!!! Defintly was worth trying this out before driving 2 hours to apple!!

The fix is very simple -.-

Plug the earphone back in, then while pressing and holding one of the volume buttons you plug out the earphone.

I just picked up a USED (no warranty) Mid 2010 MBP with this issue.  I have read the many threads all over the web and tried EVERYTHING and nothing has worked.  Even headphones are flaky, you have to jiggle them to get audio so it sure seems like a bad jack.  I used to a great solderer but at my "advanced age" I'm not as steady as I can be. 

I've tried (among other things):

Blowing into the jack with a can of strong compressed air

Diddling with toothpick, q-tip (cotton removed) and any other device I can insert into the hole. 

Twisting and shouting, shaking and cajoling.  No luck. 

I have a fresh clean install of Mavericks on a new SSD with nothing installed so it isn't a software problem.

I wish I knew which soldering pads on the mother board need to be bypassed or shorted to disable the switch as I have no use for the headphone jack. I primarily want to be able to use the speakers for Skype.

Seeing as I paid under $300 for the MBP it doesn't make sense to have Apple repair it as it would probably cost twice that,  Other then the jack the MBP is excellent and was a good deal.

What I don't understand is why the speakers work for the startup sounds.

One final step - the problem is likely that the internal switch is sticking. If blowing and compressed air doesn't work to clear the gunk, spray some WD-40 into the headphone jack, then plug and unplug headphones into the jack about 5-10 times. After doing this, my speakers are working again just fine, and they properly switch between headphone and speaker as they should. (Other methods suggested here didn't quite solve my problem.)

Tried all options nothing worked.  Sprayed a small amount of battery terminal cleaner into head phone jack. inserted head phones into port multiple times and rotated audio was restored.

thanks for the tip

I (as many others) have been trying to figure a solution to this problem as the toothpick method seemed only a temporary solution but seems to strike at the root of the problem.I have found a low-tech solution by inserting  a plastic anti-dust audio plug in the audio jack. This seems to do the job as it pushes the audio mechanism without closing the circuit. Problem solved!

Your solution of *pressing a volume button while removing the headphones out of the jack* totally worked for me! Thank you so much.

Hey,

I had this problem too with my mac. I tried blowing in the headphone jack and deleting the two files mentioned, and also tried tilting my mac at 45 degree.

I just inserted my headphone into the jack and removed it...kept it doing for about 5 times and it solved the problem!

Vedant Jain

Just got a Mac and I'm experiencing the same concern.

I feel robbed. It's amazing to have to deal with this kind of software behavior, definitely something you're no waiting for when u get this kind of gear.

Can't wait for the next behaviors of the kind, seemingly common to Apple (who don't seem to care about...)

By the way, "fix" it by filing something inside the jack in is absolutely ridiculous.

Get a PC with xp on it...

I had the same problem on my Macbook Pro 6,1 running 10.6.8

I don't use the Digital Output so decided to disable it in the driver.

Here's what I did: (proceed at your own risk !)

Open a Finder window, navigate to /System/Library/Extensions

ctrl-click AppleHDA.kext and select Show Package Contents

Open Contents folder

Open PlugIns folder

ctrl-click AppleHDAHardwareConfigDriver.kext and select Show Package Contents

Copy Info.plist to the Desktop

On the Desktop make another copy and rename it Infooriginal.plist .

Open Info.plist with Property List Editor (if installed)

If you don't have it, open with Pref Setter from:

http://www.nightproductions.net/prefsetter.html

Click the triangle to the left of IOKitPersonalities

Click the triangle to the left of HDA Hardware Config Resource

Click the triangle to the left of HDAConfigDefault

Click the triangle to the left of Item 3 (using Pref Setter)

                    or Item 2 (using Property List Editor)

You're in the correct place if it says Codec - Cirrus Logic CS4206

Opposite ConfigData, click the (Data Item) in Pref Setter

After the first 32 figures enter 00 87 d0 00

ie 00172000001721000017226B00172300 < here

cmd-S to save the changes, then drag or paste the Info.plist from the Desktop to the Contents folder in AppleHDAHardwareConfigDriver.kext

Select Replace and enter your password when prompted.

After a Restart the Digital Output is no longer an option in Sound Preferences which prevents the Internal Speakers from being disabled when the headphone jack is removed.

I don't know how to re-enable the Digital Output which isn't an issue for me but if you may want to use it in the future, you should research that before attempting this procedure.

Credits to Henry Wong at:

http://www.stuffedcow.net/macbook_audio

There's a typo in the above post.

It should read:

After the first 32 figures enter 00 87 0d 00

Don't forget (like I did !) to repair disk permissions in Disk Utility after the surgery