I am very pleased with the previous <Mac: Mute speakers, red lights at the ear plug-in> blog posts to help many people. Here are a few solutions for others that we accidentally see.
This method is suitable for DIY experts with strong hands-on ability. If none of the above methods works, this method is the final solution.
Open the lid of the machine first. For more information, see any other resources. For more information about the old version of MacBook, see here.
For example, the rightmost side is the earphone plug-in. When the external metal skin is uncovered, the upper part of the seat can be opened. See: <Strong? Http: www.bkjia.com kf ware vc "target =" _ blank "class =" keylink "> VcD4KPHA + pgltzybzcm9 "http://www.2cto.com/uploadfile/Collfiles/20140522/2014052209120324.jpg" alt = "">
It points to the small switch. If it is not broken, move it to see where it is stuck. Put it back, stick it with strong glue, or bind it with tape. You can work as long as you do not make effort in the future. Thank you for your contribution.
There is also a less violent, suitable for common users:
1. Insert an external speaker or earphone into the earphone plug-in.
2. Turn off your computer
3. Reset the SMC once and keep the insert status.
4. Unplug the device after it is started.
The last one I did not succeed in 10.8.5, but you can also try it:
1. Insert an external speaker or earphone into the earphone plug-in.
2. Press the Alt key and click the horn icon in the menu bar. 3. Select the in-ear socket as the input, so that the built-in speaker starts to work again.